STL Science Center

STL Science Center

23 September 2017

Newer Dromaeosaurs

©Nobu Tamura
It has long been hypothesized that the origin of dromaeosaurs was likely to be found in Asia where preservation is fairly good and basal characteristics of dromaeosaurs are found in a number of fossils. Mongolia and Northern China are prominent sites of these fossils, so it was not much of a surprise when Turner, et al. announced the description of what was called one of the most basal dromaeosaurs discovered to date in 2007, Mahakala omnogovae. Its name directly references the Tibetan Buddhist protector deity Mahakala and the southern province of Ömnögovi in Mongolia. The type specimen is a small adult, approximately the size of Archaeopteryx, consisting of portions of the cranium, limbs, vertebrae, pelvic, and shoulder girdles. Distinctively, Mahakala possessed a second toe on the hindlimb that was expanded and highly recurved. The small size of the dromaeosaur makes it a little less frightening than its larger descendants and cousins, but fear is relative when you are small enough to be the prey of this early diminutive dromaeosaur.

22 September 2017

Looking Similar

Peteinosaurus illustrations are like many pterosaur illustrations in that they all look very similar and very often depict a flying reptile with wings spread and mouth open. The less popular version, which still turns up fairly often, depicts the pterosaur in question sitting on a branch or the ground ready to vault into the air. Somewhere in between there are hunting and swooping images. This image by Nobu Tamura captures the moment after swooping and chasing and the moments before our friendly Peteinosaurus would be ready to again launch (or fall) from the branch to take to the air once more.

20 September 2017

Headless Pterosaurs

Despite well preserved slab fossils, not a single specimen of Peteinosaurus possessed an intact skull or any skull actually. The teeth of Peteinosaurus are known somehow, though. Three types of conical teeth are associated with the pterosaur and their shape indicated an insect based diet. The teeth and diet of Peteinosaurus are not the most unique characteristics of the fossils though. The fifth toe on each foot was elongated and had lost its claw. The toe possessed a joint that was different from the other toes of the foot. This joint allowed the fifth two to move in ways that enabled movements of the cruropatagium, the skin between the ankles, that acts as an airfoil. In a way, this structure acts like the retrices, tail feathers, of birds allowing for more precise control of flight movements. Some birds, bats, and pterosaurs like Peteinosaurus need precise control of their flights capabilities for aerial hunting in order to maintain pursuits. This cruropatagium most likely worked very much like a Barn Swallow's tail, as can be seen here:

19 September 2017

Flying Literature

The literature history of pterosaurs is quite extensive. Peteinosaurus is not neglected in that rich history either. The paper naming and describing Peteinosaurus is difficult to find online, but luckily I know where to find it. One of the most prolific pterosaur researchers of our time keeps an updated bibliography of all pterosaur research and an archive of available PDF files of the studies he has collected over the years. Rupert Wild's 1978 opus "Die Flugsaurier (Reptilia, Pterosauria) aus der Oberen Trias von Cene bei Bergamo, Italien" is only available in the original German, despite its publication in the Italian publication Bolletino della Societa Paleontologica Italiana. The study is a review of six fossil genera discovered in and around Bergamo, Italy and includes descriptive text alongside photographs of specimens and line drawings highlighting important structures from the fossils and their photographs. This is not the only review of Italian or Triassic pterosaurs featuring Peteinosaurus though. Fabio Dalla Vecchia's review of Italian pterosaurs is hosted in English and possesses a similar amount of detail, though not as much as Wild's review. However, if reading German is not something that one can do quickly or in their spare time in the near future, the descriptions of Dalla Vecchia are more than sufficient. Many of the other articles that are published which heavily feature Peteinosaurus are themselves reviews and new descriptions. Therefore, these two highly detailed descriptions of Peteinosaurus are more than enough to read today.

18 September 2017

Supporting Character on Wings

First and foremost, here is a link to the episode of Dinosaur Train that introduced "Petey the Peteinosaurus" (there are a number of versions of this but this is the only full episode that is not flipped horizontally). The first episode of the original "Walking with..." series was about dinosaurs specifically and mentioned supporting characters like Peteinosaurus (and mammals and amphibians) in passing. Peteinosaurus, however, benefited, in terms of the show, by existing during the Triassic dawn of the dinosaurs. The first episode of Walking with Dinosaurs focuses extensively on the environment that fostered the rise of the dinosaurs. This environment was populated by various protomammals and archosaurs, one of which was the "exotic hunter... Peteinosaurus" as Kenneth Branagh describes it. The short blurb about the flying reptile is not an enormous portion of the episode, but we know that Peteinosaurus is an important member of its environment. Its hypothesized role can be seen clearly in the show, as can its acrobatic capabilities.

17 September 2017

Two Movies

Peteinosaurus appears in a few television roles, but only one is relevant today. There is a second video that is relevant to today in that it relays facts and shows some relevant illustrations of the flying reptile. The cartoon that is relevant today is, as it usually is on a Sunday, a short clip from the PBS show Dinosaur Train. As usual, the alliterative name of the Peteinosaurus in this episode is Petey. The clip attached here, however, is just Dr. Scott talking about facts like height and weight of Peteinosaurus and not a portion from the actual episode with Petey in it.
The second video clip is from WizScience and is nothing but straight facts and a single view of one of the fossil slabs containing Peteinosaurus material.

16 September 2017

Flying Fun

Aerial acrobatics in the days of the dinosaurs were not conducted by birds or bats, not early on at least. During the Triassic there were a number of small reptiles capable of flight, the pterosaurs. One of the smallest, oldest, pterosaurs of the Triassic was Peteinosaurus zambelli. This small pterosaur had a wingspan of approximately 60 cm (24 in), one of the smallest known for pterosaurs, and weighed about the same as a Common Blackbird (or American Robin for North American readers). Known from fossils from northern Italy, Peteinosaurus has been well preserved mainly on three slabs of material that house very flat and fragile specimens. This is not abnormal for pterosaurs as they possessed very strong but light bones. Peteinosaurus is slightly abnormal for pterosaurs in that it is known to have possessed three different types of teeth (called tridontomorphy). These teeth were used for catching insects and hypothesized features of the manus and wing may have been highly suited to permit precision aerodynamic control of the pterosaur in flight, meaning that at least some of the insects Peteinosaurus hunted may have been flying meals.

14 September 2017

A Furry Star

Whenever any fossil is found in a level of completeness like that of Castorocauda it becomes a little bit more famous than other fossil animals. Sometimes this popular knowledge of a taxon remains and continues onward for centuries (T. rex, etc.) and sometimes it lasts mere moments (Morganucodon, perhaps, for the non-professional readers). Castorocauda appears to have retained some of its initial popularity, but has generally been mostly lost to the public over the past decade. In that time, however, Dinosaur Revolution and Dinosaur Train both capitalized on the discovery and description of this small swimming mammal. Arguably, Dinosaur Train did a much better job of describing and showing the features of Castorocauda, as we can see in the clip below. Dinosaur Revolution mentioned some of the characteristics of Castorocauda, but these were largely ignored in its animation. The tail and overall body shape can be seen clearly, but the show depicts Castorocauda running through a forest and into a hollow tree whereas the Dinosaur Train scene below takes place at the edge of a marshy lake possibly like the area from which the nearly complete Castorocauda fossil was recovered. Granted Dinosaur Train is much more educational and thoroughly proves it by comparing mammals against mammals and mammals against dinosaurs and pterosaurs as well as describing the characteristics of Castorocauda in great detail (for a kid's show).

13 September 2017

Fur Anatomy

The fur of Castorocauda has been described as consisting of two kinds of mammalian fur: guard hairs and underfur. These two kinds of fur seen in the fossil of Castorocauda provided some of the first very solid evidence of a furry mammal in the Jurassic; evidence of mammalian traits and some samples of fur and hair have been seen prior to this, but, as with feathers, this was one of the first truly wonderful collections of soft tissue that is generally lost to fossilization processes. It is also one of the earliest mammals recognized to have possessed the modern mammalian fur arrangement and follicle structure. The first kind of fur that was definitively recognize in the fossil is what is known as underfur or undercoat. This fur is short, flat, curly, and dense. It is this hair that keeps mammals dry in water and warm in winter. These rather different capabilities of this layer of fur are similarly achieved through the trapping of dry air against the skin which both repels water and maintains a buffer of warmth against the cold of the environment. Underfur serves as a thermoregulatory buffer for the skin and, overall, whole organisms like us and Castorocauda from the temperatures outside our bodies.

This is in contrast to the role of the second layer of fur recognized in Castorocauda: guard hairs. Also colloquially referred to as the coat, guard hairs are the main centers of pigmentation in fur. Display patterns, camouflage, and the shininess of a mammal's fur are reliant on the pigments collected in the guard hairs; these are of course regulated by other factors such as genetics and diet as well. Guard hairs are typically long straight hairs that come to a point and, in some mammals, can be fairly coarse. It is these hairs that we notice in threat displays, when frightened, and in other moments of agitation or excitement. Guard hairs also, as the name implies, guard the body. They do not trap warmth or repel water as well as underfur (though they are capable of doing so). However, guard hairs can significantly block harmful ultraviolet radiation from reaching the skin, something that the underfur does not do as much of (possibly because of the presence of guard hair of course).

What does all of this fur mean to Castorocauda? Thermoregulation, as a small mammal, and thermal insulation, as an aquatic mammal, created enormous metabolic requirements for Castorocauda. Out of the water, seasonal shifts in temperature would have caused the animal to need more or less of a coat of fur, but may not have been so demanding that Castorocauda possessed seasonally variable coats. We can remain open to this possibility as we do not know exactly how much of a temperature shift between seasons mammals were readily tolerant of during the Mesozoic, but it may be that the shifts did not cause radical changes in coat length or color (see #7 on this list specifically). In the water, coat length changes the dynamics of locomotion and, if we consider mammals that we know to be semiaquatic, we can make inferences on whether or not Castorocauda would have benefited from having a long coat; color changes based on season may not have affected the animal at all. Most semiaquatic mammals possess short, coarse guard hairs with a few exceptions, river otters and beaver, for example, possess long guard hairs. The unique mammalian hairs of Castorocauda, regardless of their seasonal changes, pigmentation, or general coarseness, were and remain an important feature of the mammalian body plan. The fur allowed Castorocauda to stay warm all year long and to dive into waters both warm and cold to chase fish and crustaceans (or other invertebrates). Weighing in at up to 800 g (about 2 lbs), Castorocauda would have gotten a great deal of help in maintaining its body temperature in colder waters from a thick coat of fur.

12 September 2017

The Literary Accomplishments of Small Mammals

Castorocauda is one of the better preserved mammalian specimens of the fossil record. Not simply of the Jurassic fossil record, but the entire mammalian fossil record. There are a number of younger finds that are wonderfully preserved for various reasons that include age, lagerstätten preservation (tar pits and tundra finds included), and occasionally luck. Regardless, the 2004 fossil find of Castorocauda has given mammalian paleontologists a lot to study and that has given us a lot that we are able to read. Ji, et al. 2006 introduces the approximately 425 mm mammal to the world and is openly published on Science's website, allowing everyone to read it without downloading a PDF or paying for the full article. Pictures of the fossil show that the mammal was preserved in a slab of rock with only small portions of the hindlimb, torso, and neck absent from the fossil. Science also hosts an article on mammalian brains (Rowe, et al. 2011) that mentions Castorocauda and discusses the animal's integument and subsequent meaning of these hairs in relation to brain development and sensory inputs. The majority of other papers that mention Castorocauda are likewise filled with very short single paragraph or less mentions of the animal to show one point or a snapshot in the development of a system. The major paper that we have for Castorocauda, however, is extensive and describes the animal and its functional morphology in high levels of detail.

11 September 2017

Supposed Jurassic Beaver

Dinosaur Revolution was a Discovery Channel documentary that aired in 2011and consisted of four episodes that explored topics from evolution to defensive and offensive tactics of different dinosaurs. The third episode specifically examined how dinosaurs and their contemporaries hunted one another or defended themselves from predation. That episode included what some refer to as a "Jurassic Beaver", though we know better that Castorocauda was not related to beavers at all. The episode is available (for the moment) online and you can get to it below:

10 September 2017

Information In Motion

Castorocauda has few informational websites. Instead of sending people to multiple sites to learn some quick facts about this Jurassic mammal today, here is the WizScience video that contains pretty much all the information that can be found on a myriad of sites.

09 September 2017

The Not-A-Beaver Family Tree

©Nobu Tamura
In the past, at least once, we have discussed the rodent family Castoridae which includes the two extant members of beaver (North American and Eurasian Beaver both). This week we will be discussing a beaver-like animal from the Jurassic that, despite appearing to look very much like an extant beaver, was highly specialized for a semi-aquatic lifestyle similar to that of a beaver. There is also a great deal of similarity between river otters and our animal this week, which earned this cynodont mammal its specific epithet. The only animal that this animal convergently shares traits with, but not a name reference, is the platypus. The animal in question, Castorocauda lutrasimilis, actually translates to "Beaver Tail, Otter-like" and therefore directly references both similar extant animals. This animal, as stated, is actually a cynodont, a group of therapsids that appeared during the Permian and includes modern mammals as well. The closest family members of Castorocauda, other docodonts, are also extinct, with the family completely disappearing from the fossil record in the late Mesozoic. Castorocauda itself is found in 164 MA Jurassic rocks from Inner Mongolian fossil lakebed sediments. A wonderfully preserved fossil of Castorocauda was recovered in 2004 that possessed hair, including an undercoat of fur. Another difficult to preserve portion of mammal anatomy that was wonderfully preserved in Castorocauda is the delicate and tiny middle ear including the ossicles.

08 September 2017

Lacking in Illustrations

The exquisite preservation of Heliobatis is often all anyone needs to imagine this animal punting along (that is correct verb to describe ray swimming) the bottom of the freshwater habitats they called home. Few illustrations, paintings, or other media have been carried out to depict Heliobatis in action within its habitat. Another, potential, reason that there is not a high demand for illustrations of the ray is that it appears to have been quite similar to extant rays, making illustrated representations of the ray appear less fantastic and awe inspiring than many other paleo art; this is not a reason to not create art of course. It is hard to pick a single image of Heliobatis to share as a wonderful depiction of the animal today because of all of the good photos of the well preserved fossils. Regardless, if I was forced to choose one single specimen to hang on my wall (Heliobatis fossils are for sale all over the internet, by the way), I would go with the image shown here. The detail is wonderful, as usual, but in a different way than the majority of other fossils. The slab is darker, and therefore the fossil details are also darker. The higher contrast makes thee anatomical details pop out a bit more and the contrasting elements of relieved and elevated portions of stone in the slab have a more natural look to them.

07 September 2017

Anatomy For All

©Brian Greenstone
Heliobatis fossils from the Green River Formation are very nearly the epitome of lagerstätten fossils. Because the preservation is so exceptional, there is a lot known about Heliobatis and its anatomy. The life history of these freshwater rays is well known because of this as well. We know that Heliobatis most likely ate small crustaceans, fish, and mollusks because we have found teeth in the fossils. Those teeth are small triangular biting teeth that are oriented very closely together.  These teeth could have been used defensively, however; like extant rays Heliobatis had a barbed stinger on their tails. Their stingers consisted of approximately three modified placoid scales (also called dermal denticles). The placoid scales were also found on the skin of these prehistoric rays and are very similar to the dermal denticles that are found attached to the skin of extant rays, skates, and sharks. One of the other very important characteristics of that we know of from the exquisite preservation of these animals is that they were sexually dimorphic. Male chondrichthyians, including Heliobatis, possessed clasping organs that are used to fertilize the female's eggs. More can be read about this topic in various places; the shortest version can be found here.

05 September 2017

Written Rays

Many of the papers that appear in preliminary searches concerning Heliobatis either use the ray for comparison or note a collection of fauna from a given locality. These are of great worth to us in that they both require descriptive text about Heliobatis and both types of writing tend to provide or ascribe behaviors or habitat information to the sun ray. These are, in turn, both useful for understanding the organism and its environment and generating more hypotheses about the animal and its life history. As mentioned previously, the teeth of this ray are typically well preserved and they have been studied frequently in conjunction with the teeth of other fossil rays to discuss phylogeny, differences in environment, and in the context of dental evolution. In some instances, all three of these topics are discussed, to a point of course; that is a lot of information to attempt to shoehorn into a single paper. There are papers that discuss locomotion of skates and rays as well, using Heliobatis and other rays pelvic girdles to predict what their swimming will look like.

04 September 2017

Zooming In

Heliobatis, despite being well known for a very long time, is not really a charismatic animal that has garnered a lot of demand in the documentary, cartoon, or feature movies of the world. As a somewhat stereotypical looking ray, it did not really possess any anatomy that would have stood out enough to garner special attention. There are very few videos in general that have anything to do with Heliobatis. We shared some of them yesterday. The only remaining video that definitely features Heliobatis is an eighteen second video zooming in and out of one of the fossils. That video can be seen here.

03 September 2017

Skate Video

For those that lie to read their videos, there is a really informative video posted by the user Gemini Bull. The video is really a compilation of information found on all kinds of different sites online. The video and information on the video show a lot of images of Heliobatis and actually make it such that many different links would not be required to learn from this week, for the sake of keeping the post free from redundancy. One of the better sources online, that is not a video, to learn from is the virtual fossil museum. Prehistoric Wildlife also has some information though it is almost entirely taken from Wikipedia. It does have the only size comparison with a person shown online; that makes it worth a view as well.

02 September 2017

Rays and Skates

© Didier Descouens
Rays and skates are members of the Chondrichthyes, a class of animals that first abundantly populated the oceans during the middle of the Devonian period and has persisted into the modern age. Other members of the class include sharks, chimaeras, and sawfish; sharks representing the best known members of the group. The rays that we are interested in this week are some of the most well known fossil chondrichthyians from the Eocene known as Heliobatis radians (Sun skate/ray). The ray Heliobatis was originally described in 1877 by O. C. Marsh (simply as Heliobatis) and has since had four genera synonymized under the name Heliobatis. Particularly well-known from the Green River Formation, Heliobatis is best known specifically from the Fossil Lake sediments of Wyoming; many of these are housed or on display in either Fossil Butte National Monument ("America's Stone Aquarium") or the Yale Peabody Museum. The known fossils housed and displayed in those two locations are highly detailed. The details are so well defined actually the sexually dimorphic characters, defensive characters, and the feeding apparatus have all been described. Teeth are observable in many of the specimens and based on the triangular shapes of the teeth, the diet that has been hypothesized for Heliobatis is largely based on small fish, crustaceans (there are numerous crayfish and prawn fossils associated with the same formations as Heliobatis), and mollusks.

31 August 2017

Frog Prince(ss) of Popularity

Living permanently in water, Palaeobatrachus was the kind of frog that people often think of when someone suggest that they imagine a frog going about its daily routine; this or a similar idea are common things in kindergartens worldwide, I promise. This, in coordination with its revival as a cartoon character on a popular children's series and numerous entries in scholarly papers as well as short texts on frogs (such as Tertiary Frogs from Central Europe). Scholarly articles and cartoons alike appear to be enough to make this fossil amphibian popular enough for it to continue to be well known and widely distributed in image, text, and even video online.

30 August 2017

The Lungs of Frogs

The typical lungs of your average frog are similar in general shape to the lungs of other terrestrial vertebrates in that they appear as lobes of soft tissue at the end of a trachea. They are also similar in function as they allow for blood and air to interact allowing for gas exchanges within the organ itself in specialized structures called alveoli; frogs have a much lower concentration of these structures in their lungs than other vertebrates. The lungs of Palaeobatrachus were not too different from those of their descendants in function, but their morphology was considerably different. Whereas extant frogs possess centrally located lungs housed in the thorax, the lungs of Palaeobatrachus were located within the dorsal sides of their thorax. Extant frogs, of course, do not only use their lungs to breathe. Gas exchange occurs within the mouth (minimally) and cutaneously while submerged; frogs make use of dissolved oxygen in the water to exchange gases through their skin. It could be hypothesized that the dorsal lungs of Palaeobatrachus laid the groundwork for these centralized lungs and also that they aided in enhancing the development of the system of cutaneous respiration we see in extant frogs. Cutaneous respiration may have, at the time, been the main method of filling the lungs of Palaeobatrachus as well, meaning that the lungs were an added adaptive characteristic of this frog; there exist today many small terrestrial amphibians completely lacking lungs. Perhaps these lungs enabled the frog to take in a large amount of air before diving and stay submerged longer in potentially oxygen poor aqueous environments. The evolutionary history of amphibian lungs is far more complex than we have time for today, unfortunately, but there are many resources available to delve into this history.

29 August 2017

Volumes of Frogs

The number of papers written about Palaeobatrachus is well more than enough for a book all on its own. There are papers from this year that mention Palaeobatrachus and compare it to other fossil frogs, but these are not the meat and bones of the literature that details the knowledge that we have on Palaeobatrachus. There have been many different descriptions, recently even, of new species of Palaeobatrachus. The most recent descriptions, from last year, are of species known as P. diluvianus and P. eurydices; these species do not appear in any mentions of Palaeobatrachus species lists. New descriptions of fossil frogs, however, are not the only studies that have been published about Palaeobatrachus that are interesting and have made significant impact on the study of these particular frogs and fossil frogs in general. A particular favorite of mine is Roček, et al. 2006 on tadpoles and gigantism in Palaeobatrachus juveniles. A second favorite that I would recommend reading is about the diet of Palaeobatrachus. Wuttke and Poschmann 2010 describes a lagerstätte fossil of an unspecified Palaeobatrachus species with fossilized stomach contents. Those contents were made of small fish that the frog clearly captured and ingested (i.e. fish that were eaten by the frog).

28 August 2017

Short Dinosaur Train Day

Today there is only a single documentary/feature that shows Palaeobatrachus and discusses it. Dinosaur Train has an entire episode about the family venturing out on a camping trip that also features this central European frog. The family meets Patricia Palaeobatrachus during the middle of the night when they hear a strange and scary noise.

27 August 2017

Ancient Frog Links

Palaeobatrachus appears in a number of links and on a number of websites that are helpful for children and other fossil enthusiasts of course. The links range from very easy and quick reads, such as the Dinosaur Train Field Guide (which actually reads the facts to you), to more difficult passages like those found on the Prehistoric Wildlife and Encyclopedia of Life pages. The Encyclopedia of Life pages are actually heavily stocked with information about the fossils, where they originated, and what we know about the life of the animal. Anyone wanting to skip a little reading, or having the facts read to them by the Dinosaur Train conductor, there are also videos dedicated to facts about Palaeobatrachus. The easiest to find, of course, is a short from Dinosaur Train featuring Dr. Scott Sampson, as seen below (the audio of the current version available has a little echo).

26 August 2017

Fur to Frogs

©Nobu Tamura; released as Palaeobatrachus gigas
Palaeobatrachus is a genus consisting of at least two named species, P. occidentalis and P. robustus (with others being mentioned that we will explore later), of amphibian that appears in the fossil record from approximately 130 MA to 11.6 MA; Fossilworks reports a range of 70 MA to 9.7 MA and these disparate ranges will be figured out later this week. An early frog, Palaeobatrachus is known from central Europe. Specifically, Palaeobatrachus is very common in the freshwater fossils of Germany. Early frogs, Palaeobatrachus, was extremely amphibious and spent very little time out of water. A lot is know about the entire life cycle of Palaeobatrachus with all stages of life, egg, tadpole, and adult, having been recovered from Bohemian rocks. Changing temperatures and changes in available suitable water sources caused Palaeobatrachus to suffer a reduced range of habitat. This, in the end, forced the frogs into extinction as continual climate change and shrinking suitable habitat forced the frog into what would be a losing battle with other taxa and the environment.

24 August 2017

Home Field

Megalibgwilia is known in parts of the world that are not Australia, but its popularity, in the form of common popular outlets such as books movies, websites, video games, and toys, appears to be entirely lacking outside of Australia. Websites, of course, reach well outside of Australia, but dedicated sites that we have not already shared and discussed are rare and do not add too much that we have not already shown concerning the giant echidnas. One of those few non-Australian based websites that share information about Megalibgwilia is Berkley's Museum of Paleontology website. This page more specifically discusses monotreme evolution, but Megalibgwilia represents an important step in the evolution of other echidnas. A lack of other sources aside, the popular entry this week is therefore ending abruptly and is shorter than usual.

23 August 2017

Megalibgwilia's Elbow

W. H. Wesley, Humerus of M. ramsayi
Owen's original description of Echidna ramsayi, later synonymized as Megalibgwilia ramsayi, consisted entirely of a detailed look at the broken left humerus of one of the "giant" animals. Eventually crania and postcranial remains were added to the descriptive list for this single species. All of the descriptions of M. ramsayi have amounted to a fairly complete picture of this first species of the genus. The second species, M. robusta, was described by William Sutherland Dun in 1896 and consisted of mostly complete remains. Megalibgwilia robusta is the oldest known echidna and, despite being known as a "giant echidna", is slightly smaller than the largest known monotreme of Western Australian; Zaglossus hacketti. Contemporaries of Zaglossus, the two species of Megalibgwilia were geographically separated from one another and their larger cousins in Western Australia. Megalibgwilia ramsayi appears to have been prominent across mainland Australia and extended to Tasmania whereas M. robusta has been restricted, so far, according to fossil remains, to New South Wales. The two species possessed snouts that are more well suited to probing and grabbing insects than grasping and probing for worms like the Zaglossus group of echidnas. As contemporary species, Megalibgwilia and Zaglossus may have possessed overlapping ranges, making diverse diets for the two groups of animals important in minimizing competition for food sources.

22 August 2017

Short on Papers

There are not many papers hosted online featuring Megalibgwilia. Considering that these echidna ancestors have been known and described for almost 150 years, the lack of modern articles is somewhat sad and almost depressing. There are plenty of articles that make passing mentions of Megalibgwilia or compare the "giant echidnas" to extant members of the genus. One of the original articles describing Megalibgwilia by Owen in 1883 originally named the animal Echidna ramsayi and consisted of less than a half page of text. That abstract of a lecture by Professor Owen can be viewed in the archives of the Proceedings of the Royal Society here. Unfortunately, Dun's 1896 description of the other species, Megalibgwilia robusta, has not been hosted anywhere online. Print copies may be nearly impossible to find as well given the age.

20 August 2017

Mega Facts

Megalibgwilia is an unusual animal for a variety of reasons. Some of these reasons are detailed in the facts that are know about the animal and shared on various websites and fact pages. There are a number of sites we have used before and many that many among us may have never heard of before that host files, short essays, and illustrations of the two species of this genus. The first of these familiar sites which appears in a search is the Dinopedia. Despite this animal clearly being a monotreme, a type of non-placental mammal now represented by only extant echidnas and the Platypus, the Dinopedia entry is fairly comprehensive and discusses Megalibgwilia almost identically as sources like Wikipedia. This makes it neither more nor less useful than Wikipedia of course. Wikispecies entries for the animals are taxonomically useful, but again, this information can be found in Wikipedia as well. A slightly more detailed history of taxonomy is available on the Fossilworks site which also provides some locality details for known fossils as well. One of the most interesting new sites is the Australian Broadcasting Corporation's site discussing the extinction of megafauna in Australia. While it does not specifically discuss Megalibgwilia exclusively, this site does discuss the environment it lived in and how it may have been subjected external and internal pressures leading to its extinction.

19 August 2017

Monotreme Party

In looking for  new animal this week we are going out of our normal range and into the time of the mammals. Becoming extinct approximately 50,000 years ago during the Pleistocene, the tachyglossid (a group that includes the extant genera of Echidnas) Megalibgwillia consists of two species, M. ramsayi (Owen, 1884) and M. robusta (Dun, 1896), and represents the oldest known echidna genus found. Both species are often referred to as the "giant echidna" but recent evidence shows that they are approximately the same size as the largest living echidnas rather than immense fossil animals, respective to extant echidna. Both species are represented by largely complete fossils and, because we know basically what the animals looked like, we can state that they were most likely as bizarrely intriguing as extant echidnas.

17 August 2017

Somewhat Well-Known

Conchoraptor has made a larger impact than many other dinosaurs. It is still not a widely known dinosaur, but it is known throughout the dinosaur community to a greater extent than many other dinosaurs. Conchoraptor is a dinosaur that is more well-known online than it is in most other media. It has appeared in books, illustrations, and has been featured in a few privately made tribute videos, but it does not appear in any games, movies, or documentaries. Having little to share in the vein of popular culture, there is at least a single private video that can, and is, shared here to show a variety of illustrations of Conchoraptor. As always, remember that these videos sometimes mislabel taxa unintentionally and that some of the images may not represent Conchoraptor as well as others. These images are open to interpretation as well.

16 August 2017

Feathers and Genders

At least one site mentions that Conchoraptor remains have been discovered with attached feathers. These feathers have been described sparingly, but have been described as sexually dimorphic characters of Conchoraptor. Sexually dimorphic characters are typically most reliable in adult animals. The assumption with the assertion that the feathers represent dimorphism is that they most likely came from adult specimens. One of the hypotheses of discerning adults from juveniles and sub-adults in Conchoraptor is less concerned with feathers and sexual dimorphism and more concerned with the crest on the cranium. Most oviraptorids possess a large crest along the midline of the skull that is larger rostrally than caudally. The original material lacks a crest entirely and remains recovered later also appear to lack crests or possess very minimal crests. The hypothesis that crests grew as the dinosaur aged are not abnormal or new, but without known fully adult specimens possessing full crests, we can neither, as yet, support nor refute that hypothesis. However, if evidence comes to light to fully support this and the hypothesis concerning dimorphism and feather morphology, then we will know a lot more about the life histories of these animals.

15 August 2017

The Brains and Skulls

Brains and other soft tissues are of great interest to scientists in extant and fossil specimens. There are a variety of ways to study organs in extant specimens and many of those methods can actually be applied to fossil specimens as well. Many of the methods used to investigate fossil soft tissue systems originate in studies of the soft tissues of extant organisms. These are systems that we can readily devise methods for and test out the methods on. Interpretation of the results can be compared with observations of behavior and organ use in extant animals as well. These model organisms and their organ systems allow for inquiries into similar systems in fossil animals. These steps result in studies such as Kundrat 2007 which looks at virtual brain models of Conchoraptor derived from CT scans of the skull. The scans are used to create virtual endocasts, or models of the negative space of the skull where the brain would have been in a living Conchoraptor. Endocasts show scientists potential lobes of the brain (assuming that the skull retained its original dimensions during the fossilization process). Kundrat 2007was able to identify characteristics of the brain that Conchoraptor appears to have shared, or at least approximated, with the brains of birds. Additional studies of the skull have been undertaken which look at other organ systems of Conchoraptor and use some similar methods. Kundrat and Janacek 2007 explored the hearing capabilities as well as the structure of the skull of Conchoraptor. They described pneumatization and sinuses of the cranium (another avian-like feature). This study also described and analyzed the bones surrounding the tympanum (eardrum). Recesses in the bone helped to describe the tympanum itself as well as the different portions of the ear. Specifically, Kundrat and Janacek were able to describe distinct proportions and geometry of the inner and middle ear of Conchoraptor and infer the hearing capabilties of the dinosaur.

13 August 2017

The Video File

There have been, as we have gotten more and more into the lesser known dinosaurs, fewer and fewer resources available at any given time. This has been related to the popularity of given dinosaurs, of course, and has not really made our job any easier when it comes to sharing interesting and new sources. However, we have a stable of consistent and helpful resources that we can typically fall back on that are reliable and accurate, which are far more important than new and interesting. For that reason, rather than posting a small number of websites all sharing the same basic information about Conchoraptor today, I would much rather share a single video, produced by WizScience, that summarizes all of those pages and does so over a series of illustrations and photographs.

12 August 2017

Shell Stealing Dinosaurs

Known from the Nemegt Formation of Maastrichtian soils of Mongolia, specifically the Red Beds of Hermiin Tsav, the conch stealing oviraptorid Conchoraptor gracilis. Barsbold 1986 described a partial skeleton and skull of an oviraptor which, like its cousins also discovered by Barsbold and the Polish-Mongolian expeditions of the 1970's, is a victim of the hypotheses of many scientists that the oviraptorid dinosaurs were stealing eggs rather than incubating eggs. The name Conchoraptor reflects Barsbold's hypothesis that the animal's lack of dentition was indicative of a diet that was rooted in mussels and other shellfish rather than eggs. This dietary hypothesis was unpopular at the time, though we now know that oviraptors, whether they fed on mussels and clams or not, were not feeding on the eggs that they were found with.The lack of crest, seen in this representation of the skull, is thought to have been a result of immaturity in the described holotype. This hypothesis will be explored during the week as we explore Conchoraptor.
©Jaime A. Headden
Creative Commons Attribution 3.0 Unported

10 August 2017

Fish Foods

©Florida Museum of Natural History
It has been determined, or rather hypothesized, that Enhydritherium had a mainly piscivorous, or fish-based, diet. This was based on the fact that Enhydritherium possessed bones in its front paws that are more similar to extant fish catching otters than to its ancestors which are thought to have lived on land and did not eat fish regularly. Modern fish catching otters use their mouths to catch their prey whereas the ancestors of Enhydritherium used their hands to catch and grab food items; this means that the hands of Enhydritherium and modern otters are not as adept at grasping and handling food items as their ancestors. Enhydritherium also possessed large attachments for neck biting muscles and, as a direct relation, probably had extremely large and powerful neck muscles. These would have been used to attack prey quickly and hold them as the otter then left the water to secure and feed on its fish prey. These neck and biting muscles were very important for Enhydritherium because it was not capable of chasing its food in the water. Poor swimming adaptations in the hindlimbs made Enhydritherium good at wading into water and escaping from the water, but unable to chase aquatic prey. The hindlimbs of the animal were much more adapted to terrestrial locomotion. As such, it was capable of long overland journeys like that which Tseng, et al. 2017 describes as a hypothesis of migration between the bicoastal populations of Enhydritherium.

08 August 2017

Otters and the Ocean

Due to being found near a coast and looking like their extant descendants, Berta and Morgan's initial description of Enhydritherium was heavily angled toward portraying the skeletal remains as those of a large ancestor of modern otters. Their description was not wrong, of course, and Enhydritherium is known to be one of the largest otters, fossil or extant, that has been recorded. As a large sea mammal Enhydritherium has garnered attention throughout the time that it has been known to science. This has led to a number of studies describing different aspects of the animal's life history. The most all encompassing study discusses, describes, and analyzes the osteology of the otter in order to describe its paleoecology; Lambert 1997. This is a fairly typical order of events in describing fossils and the world in which they lived that, in turn, allows for inferences concerning the interactions of this particular species both intra- and inter-specifically. What helps even more, of course, is the discovery of additional remains. Depending on how and where the remains are recovered, new answers can be found to old questions or new questions can be developed. In the case of the Mexican dental remains that we have seen earlier this week, old hypotheses have been refuted and new hypotheses generated concerning the movement of this otter. Tseng, et al. 2017 refutes old hypotheses of migration that include Arctic and Central American Seaway dispersal of Enhydritherium between what are now Florida and California. A lack of fossil evidence from either region is deemed troubling as supporting evidence of such migratory routes. However, the trans-Mexico route does possess fossil remains and, with a skeleton that appears to support terrestrial travel over long distances, also seems suitable for Enhydritherium.

07 August 2017

News and Finds

Furry extant otters are often described as adorable, mischievous, and sometimes simply with the word "awwww." The newest discovery of Enhydritherium fossils could possibly be described using those adjectives, but likely there is nothing that most people would find adorable about the teeth discovered in the Mexican wilderness. However, those teeth were the diagnostic element of the fossil that identified the animal for the crew. As Dr. Jack Tseng recounts, he recognized the teeth as carnivoran and another member of the field crew recognized the teeth further as belonging to an otter. Rather than summarize everything that he has told reporters, though, everyone should watch this video instead.

05 August 2017

Amazing Otters

Fossil mammal make appearances here from time to time. This week is one such time when mammals will be featured exclusively. Known from sites in California, Mexico, and Florida, and described initially in 1985 by Berta and Morgan from a Floridian specimen, Enhydritherium terraenovae was a North American otter dated from approximately 9.1 to 4.9 MA. The majority of sites where this otters fossils have been recovered are in Florida, but the newest discovery was made in the Juchipila Basin of Central Mexico. This find suggests that these otters not only successfully lived on both coasts, but that they may have migrated between the coasts as well. Unlike extant otters, Enhydritherium was not yet particularly aquatic, which enabled the animal to conduct movements across expanses of dry land in ways that extant otters would find both improbable and, most likely, impossible. Not many interpretations of this large otter, an estimated 16 kg (35 lbs), exist; however, its skeleton suggests that it already had a "weasel-like" body plan and was elongated, compact, and close to the ground. It may have appeared very much like Potamotherium but was likely more stocky and larger than this more recent member of the otter family.

04 August 2017

Interesting Interpretations

Figure 1: Old school Melanorosaurus herd with gracile forelimbs.
©Zdeněk Burian (1905 — 1981)
As an early sauropodomorph, Melanorosaurus has been treated in many illustrations as a proper sauropod. In a few illustrations it has been treated more as what was once properly called a prosauropod; meaning that it showed Melanorosaurus as a sauropod-like animal with more gracile forelimbs which look as though they may have been capable of reaching for food and potentially grasping items (Figure 1). Unfortunately, this is less likely than a more sauropod-like body plan. The Natural History Museum of London features an illustration that portrays Melanorosaurus as a stereotypical sauropod with a body shape similar to a diplodocid; . We would assume, with this interpretation, that the back possesses a hump of fat in the middle portion. That, of course, is not unrealistic, as it has occurred in extant and fossil animals numerous times. The kind of back shape that we expect from the skeletal reconstruction, without a hump of back fat, is well represented by Josep Zacarias' black and white illustration of Melanorosaurus. I have a number of favorite illustrations of Melanorosaurus that show varied amounts of the back fat hump; both the lean and fattened versions of the animal are acceptable and offer their own interesting versions of the potential life history of Melanorosaurus. However, the most interesting of those images, to me, is John Conway's image of a herd at a drinking hole. The animals possess neck wattles not shown in other interpretations and are portrayed in various postures across the image and in all plains of the image. A couple in the background are even rearing up on their hindlimbs. The scene has a lot of little activity in it in all corners.

03 August 2017

Anatomy and Popularity

Some may have noticed that in the past few weeks I have missed days of writing now and again. These missed days are intended and do not in any way attest to a lack of interest in subject matter or the continued existence of this work. They do reflect the amount of time available to me to write on some days but more likely than not, they are related to the amount of information in existence online or in my personal print library available on any given species of fossil animal. Melanorosaurus, for example, is an animal with fewer links, videos, and mentions in the literature than an animal like Tyrannosaurus and some days the information to be presented is less than is optimal for a stand alone entry.

©Scott Hartman
Melanorosaurus has gained some popularity in recent years. Many illustrations, commemorative stamps, and a number of videos (including one in Spanish) have been designed, created, and released that feature Melanorosaurus. The low number of fossils that have been recovered have not hindered entire skeletal recreations either; this is the case for the majority of fossil species of course as many animals are reconstructed and illustrated with hypothesized skeletal elements inferred from related or at least similar species. Hypothesized skeletal reconstructions are more informative when they include a representation of the known fossil materials, such as that shown here.

01 August 2017

On Paper

A big year for Melanorosaurus recently was 2007. In that year both the forelimb and the first complete skull of the early sauropodomorph were described using new methods and new technologies. These new papers are not readily available online, but with a little digging they can either be found or the volume containing them can be purchased. The skull and forelimb papers both, for instance, are available via Wiley as individual articles in a larger publication that can be purchased at this link. The price tags on scientific literature are always a little higher than many other publications; despite what it looks like, that is actually not a terrible price. There are books that can be mostly read online (and are also available for purchase) that contain Melanorosaurus descriptive articles. The postcranial specimens that have been designated as members of Melanorosaurus are described by Galton, et al. in the 2005 book "Thunder-lizards: The Sauropodomorph Dinosaurs" and much of this chapter is free to view through Google books. There are missing pages, as there are with many Google books, but typically these are illustrations, graphs, or other figures and not too much text is missing; lost content is unfortunate either way of course. Melanorosaurus continues to be a heavily studied animal outside of textbooks and special publications though. There have been osteological studies published in the Journal of Vertebrate Paleontology abstracts (stemming from a conference presentation).

Possibly one of the more important papers for Melanorosaurus in the past decade is de Fabregues and Allain 2016. This paper explores new material attributed to Melanorosaurus. In so doing, the authors revise the position a species of Melanorosaurus and name a new genus. Despite this paper being largely about splitting taxa, a lot is said about the genus and the anatomy of the dinosaur. This makes it very informative for our purposes this week.

30 July 2017

Video Facts

Melanorosaurus is the kind of dinosaur that we do not hear about an awful lot. Therefore, it is a little odd to see any videos about this relatively unknown, to the general public, dinosaur. There is, though, a WizScience video that exists that summarizes a number of facts and shows a number of illustrated interpretations of the dinosaur. There are also websites that mention Melanorosaurus and share relevant information. These include favorites such as Dinosaur Jungle, KidsDinos, and Prehistoric Wildlife. The last page, Prehistoric Wildlife, even has future reading listed on the page, which is quite useful for later.

29 July 2017

Early Sauropods

©SteveOC
In the Late Triassic of South Africa herbivores were already becoming enormous animals with strong limbs, large bodies, and small heads. Melanorosaurus readi, Haughton 1924 was a basal sauropodomorph that is thought to have looked much like its descendants and could have possibly fed and lived in similar ways to at least some of its descendants. Large enough to have left facultative bipedal locomotion to its ancestors and adopted obligate quadrupedal locomotion, Melanorosaurus was one of the first members of the family of herbivorous behemoths that would later be known as sauropods. Based on syntype (two specimens used to describe a single taxon) materials from the Elliot Formation of Black Mountain (Thaba 'Nyam) in Transkei, South Africa, Melanorosaurus is not well known despite being described from a femur and two skulls. This constitutes more material than a number of other fossil animals, but is nonetheless minuscule and makes Melanorosaurus problematic in a number of ways. regardless, as one of the earliest assigned members of the family of sauropods, it holds an important place in the family tree and provides clues to the steps of evolution between the earliest dinosaurs and the giants they eventually became.

28 July 2017

The Faces of Sinosauropteryx

The pudgy little fluffball that Matt Martyniuk illustrated, and is photoshopped into the image shared on Saturday, is only one version of this well known dinosaur. It may be among the most adorable recreations of the feather covered non-avian dinosaur, but it is not the most dynamic nor the most thought provoking interpretation of the animal. It is not, thankfully, a skin and bones dinosaur, though this interpretation also exists. The interpretation is done in an older style that is no longer considered acceptable in scientific interpretations of fossils. It is worth looking at to see what the 1990's version of Sinosauropteryx would have looked like though. Instead of remaining on that interpretation though, here are some more realistic interpretations. The interpretations of Emily Willoughby and Julius Csotonyi both feature feathered Sinosauropteryx in wooded areas. However, the styles are different, making the feathers and dinosaurs look very different. Each version shows Sinosauropteryx in a different light and they both have their high points and low points. Enjoy both for their different reasons.

26 July 2017

Obvious Start

Photo by Sam Ose
Creative Commons Attribution-Share Alike 2.0 Generic
After the discovery of the slab containing the holotype material of Sinosauropteryx was initially discovered one of the more important characteristics of the animal's anatomy was immediately visible. The impressions of the filaments appeared as a reddish brown band of small fibers extending from the crown of the skull to the tail. Some of these fibers are seen on the ventral edge of the tail as well. These are also visible on the counter slab and on both slabs the disorganized appearing fibers are slightly removed from the spinal column. This gap has been hypothesized to represent the area where muscle and skin would have existed during life. The missing soft tissue would have, therefore, held the proto-feathers before death. These proto-feathers, as they appear in the fossil, look like a mohawk stretching the length of the small dinosaur's body. Due to their disorganized structure, individual filaments have not been studied. The body was covered in two described filaments; however, the hypothetical types of filament (referred to as thick and thin) have not been entirely validated. However, the thicker filaments are thought to be stiffer than the thin filaments. Thicker filaments also lie at angles to these thinner filaments whereas the thin filaments are parallel to one another. All of these filaments would have made for a short down-like layer of proto-feathers that would have certainly kept Sinosauropteryx warm.

25 July 2017

Feathers on Paper Again

One of the original papers that describes and discusses Sinosauropteryx that we discussed and is worth bringing back immediately on this site: Ji and Ji 1996. Other articles that mention or describe Sinosauropteryx have been written since 2012, which makes because it is such an interesting and important dinosaur. Lingham-Soliar 2015 examines the postural stages of death in Sinosauropteryx. This paper describes three stages of the tail and neck as they assume what is known as an opisthotonic pose of the tails and necks. Studying the taphonomy of Sinosauropteryx is not all that has occurred in the last few years. Due to its important position as the first non-avian dinosaur positively sporting feathers, Sinosauropteryx has also been studied as a means of better understanding the evolution of the feathers. Studying the epidermis and dermis of the tail, Lingham-Soliar 2013 details the death pose (prior to his paper specifically on the death pose). Scaling and feathers and the fibers of the epidermis are all in play throughout this paper. Enjoy the reading this evening and learn some more about feathers and Sinosauropteryx.

24 July 2017

Videos Everywhere

There are a number of Sinosauropteryx videos all over the internet. There are, of course, the videos that have been shared on this blog first in 2012 and the one shown shared yesterday of the cartoon version of a Sinosauropteryx talking about itself and what it does on a daily basis; there is also a French version of the cartoon floating around. Today, rather than placing a tribute here or a random but newer collection of images we will watch some art as it's created. Gabriel Ugueto narrates his work as he creates it. Enjoy watching this illustration take shape. And color. And personality.

23 July 2017

Finding New Links

Dinosaur: ©Matt Martyniuk adapted under
Creative Commons
Attribution-Share Alike 3.0 Unported
It has been just over five years since we discussed Sinosauropteryx prima. Since that time many other illustrations, links, and opinion pieces (as well as scientific facts) have been published online in one form or another. Sinosauropteryx is one of the more famous feathered Chinese fossils. It was originally unearthed and recovered from the Early Cretaceous soils rocks of northeastern China's Liaoning Province. The rocks it comes from are specifically Jehol Biota rocks of the Yixian Formation. This is the same group of rocks that have contained animals like Yutyrannus, Psittacosaurus, and Sinornithosaurus. Sinosauropteryx stands out among its rocky neighbors for a variety of reasons. The first obvious characteristic of this non-avian theropod is that it is a very small dinosaur. As we can see in this photoshopped image that originally appeared in the 2 May 2012 post on this site which approximates the height of the animal based on description and measurements of the fossil, Sinosauropteryx was a small dinosaur. That post does not mention that it is wise to assume the image is an approximation of measurements taken, but at less than 0.5 m tall, this image is within the realm of reasonable approximations for Sinosauropteryx. The second characteristic of Sinosauropteryx that is well-known is the fact that the animal was covered in what appears to be a down-like layer of feathers and was the first recorded non-avian dinosaur to possess feathers and to exhibit that characteristic clearly in its fossils.

Due in part to its fame as a small feathered dinosaur, Sinosauropteryx is well known throughout paleontology and with the general public.This has led to more fact files, coloring pages, and other educational pages. The old links can all be found in this 2012 post. Additionally, I'm a Dinosaur has since produced (actually it appeared approximately six months after our posts here) a Sinosauropteryx episode of the popular cartoon. Enjoy the cartoon, the old links, and the black and white drawing/coloring page. There is a lot of new information to go over this week and this is a fairly good amount to start with on your Sunday.

21 July 2017

Gargoyles in the Woods

©Dinoraul
The most typical situation in which an ankylosaur is depicted is open plains or rocky habitat with woods in the background or, at most, the foreground. An ankylosaur like Gargoyleosaurus, however, requires a different background to live in. As we have learned, Gargoyleosaurus lived during the Late Jurassic which had an appreciably different climate and overall landscape than those seen around the Cretaceous members of the ankylosaur family tree. This scene of a bellowing Gargoyleosaurus in a small opening in a Jurassic forest is more accurate for the time period and where it lived than a wide open plain would have been. Those areas may have existed of course, but a dinosaur in an interesting scene rather than a wide open and low detail scene is not as exciting as seeing the vibrant scenery of the forest.

20 July 2017

Little Popularity

Gargoyleosaurus does not appear in many mainstream popular outlets at all. There are a number of books that mention Gargoyleosaurus in some capacity or another; however, none of these are exceedingly popular, mainstream, or well-regarded within the scientific community. Most of the books are actually short kids books about dinosaurs or generalized field guide-esque books that discuss the most important scientific aspects and discoveries of whichever dinosaur in particular. There are some video game references and toys and these appear in videos or on websites dedicated to toys and video games, not surprisingly. There is a rather interesting video worth sharing here that shows the resulting miniature 3D printed sculpture. Check out the detail here:

19 July 2017

Size of Early Ankylosaurs

Gargoyleosaurus was a somewhat smaller ankylosaur than its descendants and later cousins. Measuring in with a skull approximately 29cm (11in) long, Gargoyleosaurus' skull was approximately the size of a squirrel (minus the tail). The entire body of the dinosaur was estimated to be up to 4m (13.1ft). The largest Ankylosaurus were estimated to be as long as 10.6m (35ft); about 2.5 times the size of this early member of the family. Estimated weights, likewise, are radically different for this smaller ankylosaur. Gargoyleosaurus was estimated to weigh 1 tonne (2,200lbs) whereas Ankylosaurus was estimated to weigh in at approximately 6.8 tonnes (15,000lbs). Aside from the weight and absolute length of Gargoyleosaurus, the dinosaur was about the size of some common livestock. It could have certainly made an interesting large pet.

18 July 2017

Gargoyles Described

Skulls and postcrania in original descriptions are described together, but this does not mean that later in the research of any given taxa they may not be described separately in equal or greater detail and compared to diverse taxa. The original descriptive material pertaining to Gargoyleosaurus specifically refers to a description of a skull of a Jurassic ankylosaur (the article's title is indeed "Skull of a Jurassic ankylosaur") and does not mention the postcranial material specifically. Many years after this initial description, the pelvis received some individual detailed study and description. The love for the pelvis was part of a dedicated study of ankylosaur pelvic evolution and includes comparative descriptions of other ankylosaur pelves within the family tree. The paper contains a large number of figures showing these different pelves and how they are compared in the paper. Unlike the original description, this paper is open-sourced and therefore open to being read. The one paper significantly missing from reading that turns up on an initial search is a new description of the original materials. We can learn a lot from these two available descriptions, however, and will certainly make do with them.

17 July 2017

Gargoyles in Motion

Gargoyleosaurus is not much uglier than any other ankylosaurid dinosaur has been that we have looked at. Typically anything named a gargoyle or referred to as such is anticipated to have a disagreeable countenance; however, as we can see in this compilation of images, Gargoyleosaurus is not particularly hideous. The name instead refers to the gargoyle-like appearance of the skull rather than calling the animal itself grotesque. One of the earliest ankylosaurids, Gargoyleosaurus is extremely important in understanding the evolutionary history of the its entire lineage, and therefore we know a lot of facts about this large and interesting dinosaur. These facts can be found on sites like KidzSearch as easily as on the NHM of London's Dino Directory pages. Most of these, of course, are discussed in the video. The Dino Directory includes a nice little pencil drawing of the animal by Andrey Atuchin as well; always a nice little addition to a fact list.

15 July 2017

The Gargoyle Lizard

Gargoyleosaurus parkpinorum consists of two partial and undescribed skeletons as well as the holotype described by Carpenter, et al. 1998 (originally G. parkpini and edited slightly to the current form in 2001). The skeletons were recovered from the Late Jurassic Morrison Formation of Wyoming. The known described material consists of a skull and the majority of the postcranial skeleton. These materials have been restored and a full skeleton is on display in the Denver Museum of Nature and Science.
Photo by "Firsfron" released under
Creative Commons Attribution-Share Alike 3.0 Unported

14 July 2017

A Pretty Site

A number of panoramas and beautiful illustrations have been made containing or featuring Pelecanimimus. Most of these show the animal in the foreground of the image even as a non-feature animal. The best of the non-featured Pelecanimimus illustrations are actually two Raul Martin illustrations. The first features Concavenator with a small herd or flock of Pelecanimimus in the middleground crossing the central river of the scene. The second Martin image centers on both Pelecanimimus and Goniopholis. In this illustration, however, Pelecanimimus figures in as a potential dietary morsel for Goniopholis. Pelecanimimus appears in more water filled scenes such as  Roman Garcia Mora's Baryonyx illustration; Pelecanimimus appearing in a shaded portion of the illustration and can be easily lost in its position in the foreground. The dinosaurs also appear drinking from a stream in an painting by Jose Antonio Peñas. The only high quality non-water filled illustration being shared today depicts a small flock of Pelecanimimus running in a Spanish desert and was created by Mauricio Anton. Check out all of these illustrations and enjoy the imaginative scenes.

13 July 2017

Pelicans and Video Games

Pelecanimimus may not be one of the most renown dinosaurs that has been described. However, it has been modeled, used, and shown in a number of different video games. The most popular of these is probably the currently popular Jurassic World game. That game is available through Facebook and on mobile devices and, with the popularity of the most recent movie, there are a lot of digital Pelecanimimus out in the world right now. This is reflected not only in the single 15 minute video above, but in the sheer number of videos from the game that appear online.

12 July 2017

Dewlap or Pelican Pouch

The gular flap of Pelecanimimus is a key character, in coordination with the unique dental structure it possesses, of what makes this ornithomimid special. The skull of Pelecanimimus, looking at the fossil material, does not clearly show the gular flap. The images may not clearly show this under normal light, but the illuminated fluorescent lighting that is shown in Perez-Moreno et al. 1994 does show that gular flap quite well. The point of the flap, either way, was under scrutiny for a while, but the general hypothesis that that gular flap was used to corral and capture food items, particularly fish. Possibly the most interesting aspect of this hypothesis is that the teeth are thought to have aided in the capture of fish and the gular flap area was to be used to store the fish. This use would be similar to that of a bird's crop. Pelicans use their gular flap in a similar fashion, but more often than not immediately swallow their meals of fish after grasping the fish using the tips of their bills. The hypothesized feeding habits of Pelecanimimus may have indeed mimicked those of pelicans but with teeth instead of simply the tip of the beak.

11 July 2017

Backwards Day

Some days I get Tuesday and Monday backwards. Therefore, today I will share some movies with everyone instead of papers (because I shared those on Monday instead). The first video that one can find online is a motion trial animation made by José Antonio Peñas. This animation is short, but shows a fairly accurate representation of Pelecanimimus running at a comfortable speed. It may not be top speed, but this Pelecanimimus is certainly running well and the motion of the animation is well articulated. The eyes are a little bit more bugged out than one would expect in an accurate reconstruction, but it makes it a little more interesting. The majority of other videos are tributes or video game clips. There is another video showing statuary that is highly inaccurate. We will stick with this singular video however.

10 July 2017

Teeth and Ornithomimids

Few ornithomimids have teeth and Pelecanimimus is the most renowned of all the toothed mimics. The dinosaur was originally presented in a short Letter to Nature as unique and multi-toothed Spanish dinosaur. The holotype consists of the anterior portion of a skeleton including the skull and all of the cervical vertebrae. This holotype is preserved on a slab that has been shown in the description paper under induced fluorescence. The fossil is accompanied by a hypothetical illustration of the animal. This recreation and the description of the original material are discussed in subsequent studies such as Allain, et al. 2014 which describes a number of European ornithomimosaurs. Prior to this, however, Pelecanimimus was scrutinized and praised for possessing mineralized skin and muscle in the fossil matrix. This discovery was described by Briggs, et al. 1997 which determined the validity of the materials and the presence of skin impressions in the slab in addition to the mineralized material attached to the skeleton itself.

09 July 2017

Pelecanimimus Facts Shown

Today please enjoy this WizScience video that sums up many of the facts that we know about Pelecanimimus. These facts are the same found on the few websites that mention Pelecanimimus, so therefore today, in the interest of time, consult the video first and conduct searches of the internet sparingly. Also, go outside and enjoy the beautiful weather (if you do not have beautiful weather enjoy what you do have!)

08 July 2017

Mimed Pelicans

The Early Cretaceous of Spain contained many animals, including the ornithomimosaurid Pelecanimimus polyodon described by Perez-Moreno et al., 1994. This ornithomimosaurid was slightly smaller than many other, later, members of its family, measuring in at approximately 2–2.5m (6.6–8.2ft). Hypotheses of the diet of Pelecanimimus are mostly centered around the idea of a piscivorous, or fish eating, diet. It has been hypothesized that this diet is plausible because Pelecanimimus possessed both teeth, rare for an ornithomimosaur, and the remains of a soft tissue gular flap. This flap of skin stretched between the mandible and throat, just as a very similar flap of skin does in modern pelicans. Instead of flying Pelecanimimus used its relatively long legs to run from danger.
Artist description: The carcharodontosaurid Concavenator corovatus ambushing the ornithomimosaurian Pelecanimimus polydon in the Early Cretaceous of Las Hoyas, Spain. ©Durbed "Some rights reserved. This work is licensed under a Creative Commons Attribution-Share Alike 3.0 License."

07 July 2017

Unnamed Artists

A number of times in the past we have featured art by unknown artists and unnamed artists. Thankfully, for some of them, we have user names or some form of internet handle to use. This is true of the Polish artist Apsaravis, who created posted this image of a Dilophosaurus chasing a small Lesothosaurus across a Jurassic stream in Poland; this young woman from Poland pictures her homeland during the Mesozoic often in her creations. She describes the scene as the Early Jurassic of Sołtyków and larger theropod in the middle ground as "an early tetanurine theropod". Despite not specifically naming the sauropods in the background Vulcanodon, they are described as "Vulcanodon-like sauropods". Typically we show our animal of the week as the center piece of Friday's art, but this entire scene is somewhat majestic and wonderful; I could not resist sharing it with everyone.
©Apsaravis (http://apsaravis.tumblr.com)