STL Science Center
27 June 2016
Tributes of Dinosaurs
26 June 2016
Compy Facts
Compsognathus is well known and relatively popular with dinosaur lovers. Their small stature makes them somewhat of an enigma to people that expect dinosaurs to be giant lumbering animals or even giant energetic animals. Everyone has the ability to learn something new about these animals regardless of any preconceived notions or lack thereof that one might have. A number of sites have jumped on the fact sheet train for Compsognathus and we benefit from this significantly because we have multiple outlets from which to learn about this tiny dinosaur. There are straightforward fact sheet pages like About and Enchanted Learning. There are also pages written more as essays than strings of facts. These are similar, but may be of more interest to higher level readers. These are pages like the revamped and more vibrant Kids Dinos (still home of the illustrated timeline and nifty maps) and DK's Eyewitness website. There is also this video, which we shared last time we discussed Compsognathus on fact day:
25 June 2016
Old Friends... In Space
This is the last full week of June for blog purposes. The cosmonaut dinosaur for this month is the popular and previous discussed, at great length, Compsognathus longipes. The "elegant jaw" dinosaur was a small animal whose remains were recovered in continental Europe. The orange and green silhouettes in the scale drawing presented here are from France and Germany respectively. The remains of these French and German animals are the most extensively known and most complete skeletons attributed to Compsognathus. There have been random feet and legs attributed to the species from time to time; Sinosauropteryx, from China, has been described at least once as a species of Compsognathus. The beauty of the two skeletons is that both are complete and even integument is preserved in the fossils. The German specimen has been described as having fatty deposits preserved along the abdomen. The German specimen preserves this level of detail because of its exquisite limestone base. The French specimen is also encased in a limestone base but did not preserve integument with the level of precision that the German fossil has. There is more to discuss in the preservation of the animals and a lot more that has been inferred and hypothesized from these remains. It will be a full week of discussion to be sure.
24 June 2016
Charlie's Shield Lizard
Scutellosaurus was a small lizard possessing dermal scutes. Many illustrations of Scutellosaurus are similar to one another for many reasons. These reasons include the small size of the animal and the prominent use of an almost sheet-like layer of dermal scutes lining the back of the animal. These scutes feature heavily in many illustrations, in fact. As one of the defining features of Scutellosaurus' lineage the scutes are important enough that this distinctive feature of the animal is acceptably pronounced in illustration. Statuary is not different at all. The statues of Charlie McGurdy are life sized and the artist strives for realism as far as is possible with fossil taxa. The Scutellosaurus piece is bipedal and well defined; however, it also appears to suffer from the common dinosaur restoration problem of extremely tight skin. Regardless, the statue is well constructed and reasonably accurate, as far as we can be in recreating the fossil animals of the past.
22 June 2016
Walking Around
Two legs or four?Larger, later, thyreophorans are always illustrated as walking on four legs because of their immense size. There are temporary exceptions to this rule, however, as Stegosaurus is often portrayed rearing up up on two legs to get at the leaves on tall fern trees that it appears to have difficulty getting to otherwise. This is not walking, of course, but should be noted as an exception all the same. The basal member Scutellosaurus, like many basal taxa, appears to have had the ability to walk bipedally and could have been facultatively quadrupedal. This is something we commonly see in basal taxa of dinosaur families that eventually reach enormous sizes. There are many reasons that this kind of morphological occurs. Most often, as in this case, it is partly because of the small size of the basal members of the eventually enormous taxa. Scutellosaurus started off as one of those extremely small taxa and this may explain entirely why it appears to have been mostly bipedal. This could also be an artifact of the known skeletal elements.
©Jaime A. Headden |
21 June 2016
Pride of Arizona
Papers are written on a regular basis about dinosaurs from many different regions and specific states. Not many of the dinosaurs that we have discussed here include reference to Arizona. There are a few, but of those, Scutellosaurus is one of the most prolifically written about. These papers do not include the description paper but many papers from that long ago (almost 35 years ago) have not made their way to the internet and electronic hosting still. We do not expect they will be any time soon, however, there are still a number of other important papers that can be read about Scutellosaurus online. These include redescriptions of new material that is attributed to the dinosaur discovered approximately 16 years ago. Rosenbaum and Padian maintain the position of Scutellosaurus and attribute the new material to the dinosaur despite the incompleteness of the previously described skeleton. Other papers mention but do not feature Scutellosaurus. There are papers on herbivory in dinosaurs and descriptions of the thyreophoran family. Finally, it is important to note that Edwin Colbert revisited his original description and discussed Scutellosaurus in the Third Annual Fossils of Arizona Symposium. The original restoration is presented again in the portion of the paper discussing Scutellosaurus. It is an informative skeleton but the description of the material is more useful for understanding the animal. The visual helps of course.
20 June 2016
Scutellosaurus' Other Videos
19 June 2016
Facts on Plates
Scutellosaurus is a curious little thyreophoran dinosaur. Being a small dinosaur within the base of the branch of that family, Scutellosaurus has garnered a lot of attention both professionally and from the dinosaur enthusiast community. That allows us to have a large pick of fact pages and short essays about the tiny little armored dinosaur. There are sites with simple fact files like About and Enchanted Learning. The Dinosaur Jungle site presents the same facts in paragraph form rather than as a simple listing of facts whereas Kidzsearch adds a small amount of information to the short paragraphs. Scutellosaurus also is popular enough that it has been illustrated in an episode of I'm A Dinosaur, featured below.
18 June 2016
Before Plates
©Pavel Riha |
17 June 2016
Dilong's Popularity
Small tyrannosaurids are popular dinosaurs for good reason. They represent what will become, or in the instance of juveniles already are, a group of enormous carnivorous dinosaurs that captivate the information. Combine the fantastic size and terror of these dinosaurs with the fantastical imagery of feathers and scales mingling across the different regions of the tyrannosaur body and suddenly we have a majestic and terrifying animal that the public loves. Smaller versions, the ancestral forms, are even more peculiar, because they are very tyrannosaurid in shape, but much smaller in all dimensions. Dilong and other base-of-the-tree tyrannosaurids also possess a slightly more generic body plan that is similar to members of earlier clades, making their mixture of tyrannosaurid and "other theropod" features curious but intriguing.
©Robinson Kunz |
15 June 2016
Feathers of the Dragon
Typically a dragon does not have feathers, but Dilong paradoxus is not an ordinary dragon and it is indeed covered in feathers. A number of skulls and apparent ontogenetic stages of remains have been recovered belonging to Dilong. The feathers of Dilong were concentrated around the skull and the tail specifically. These feathers were simple feathers potentially even protofeathers rather than full fledged feathers capable of flight. Instead, as protofeathers, these structures were more likely used to maintain body temperature. Lacking extensive display feathers, the homeostasis hypothesis is even more likely. Because of the feathering and evidence of other tyrannosaurids skin covering impressions, Xu, et al. 2004 hypothesized that all tyrannosaurids had multiple different regions of unique skin coverings. The reason we only see on in the Dilong skin impressions is because of this multifaceted regional covering and the lack of other regions becoming impressed in the fossil slab.
14 June 2016
Describing Dilong
The description of Dilong by Xu, et al. is a short but thorough work. The paper addresses the anatomy of the fossil and provides clear photographs to go with the description as well as line drawings where needed. The burgeoning tyrannosaurid features of the skull are wonderfully detailed in the line drawings. Feathers are also discussed in the paper. A reconstruction of the present skeletal elements brings together the end of the paper just before the feather material is discussed. This paper is worth reading, and it is a short read, partially because there have been no other papers dedicated directly and solely to Dilong and also because it was written in wonderful detail and with precision.
13 June 2016
Dilong Liked Mammals
The Science Channel had a sensationalist documentary pitting dinosaurs against mammals on air in 2007. One epsiode of that series featured small feathered theropods hunting slow and ponderous small mammals of the Cretaceous. One of those theropods was Dilong, of course, and is depicted as hunting in small packs. In the video Dilong also has a significant and respectable jumping ability, though this is not often mentioned elsewhere and may be somewhat speculative. The anatomy is well represented despite the strange leaping behavior. The inferences of a good sense of smell are regularly discussed in tyrannosaurs and have been extrapolated to Dilong, though it did possess an open antorbital fenestra, which would house the nasal soft tissues and any associated sinuses. Imaging of the brain endocast, to determine the approximate size of the olfactory bulb, has not been conducted to my knowledge. Many studies examining the sense of smell in theropods have been published that can be applied to Dilong, however.
12 June 2016
Dilong Facts
Dilong is a popular dinosaur for a number of reasons, the least of which is the relationship between Dilong and Tyrannosaurus. Despite the distance of that relationship, tying any dinosaur to T. rex makes it automatically popular. This has translated into many fact pages on the internet. There are expected pages on sites like About and Dinosaur Jungle. There are a lot of other pages as well as WizScience (the computer scripted fact) videos that we have shared here a few times.
Despite its popularity, Dilong does not appear in a lot of other videos online. There is a documentary with the dinosaur out there somewhere, and we will try to find at least clips of it to share tomorrow.
11 June 2016
A Paradoxical Dinosaur
The confusing nature of the small Chinese dinosaur Dilong paradoxus is probably one of the smallest dinosaurs that could have been referred to as the "Emperor's Dragon." Originally described as an early ceratosaurid tyrannosauroid Dilong is certainly a paradox. More recent descriptions of the small dinosaur have removed the proceratosaur title from the descriptive taxonomy of Dilong. Both hypothesized phylogenies place Dilong as a predecessor, an ancestor potentially, to the line leading up to Tyrannosaurus. Dilong also has the distinction of being one of the clearest visible feathered fossils that has been recovered. The original fossil is a very detailed composition of the death of this wonderful, but unfortunate dinosaur.
Type Specimen ©Kabacchi |
10 June 2016
A Forgotten First
Ten years ago Salgado and Gasparini described Antarctopelta oliveroi exactly twenty years after it was discovered on James Ross Island in Antarctica. In 1986 dinosaurs from Antarctica were not a thing. Antarctopelta constitutes the first dinosaur fossil remains recovered from the continent. A number of other dinosaurs have also been unearthed in Antarctica, including Cryolophosaurus. The majority of the fossils are even less known and more forgotten than Antarctopelta. The timing of naming the dinosaur most likely led to these circumstances; Cryolophosaurus was named eight years after the discovery of Antarctopelta rather than twenty years. Our final illustration for the week is something of a capstone on the two well known Antarctican dinosaurs. A week and five years ago Alain Beneteau was featured in a post with two drawings of Cryolophosaurus. neither of which could have included an Antarctopelta meal for the large theropod. Geography and time separated the two dinosaurs by approximately 110 million years. There were certainly food items for the theropod and predators of the giant herbivore in their respective times, but no battles played out between the two. Our final Antarctopelta of the week shows how lonely its fossils are at the moment. Much of Antarctica is still unexplored though and more fossils could be uncovered in the future.
©Alain Beneteau |
08 June 2016
Extrapolating Armor
In the Late Cretaceous nodosaurian ankylosaurs were covered with armor and many of these dinosaurs even had larger extended pectoral (shoulder) or pelvic horns that could be considered offensive weapons. It should come as no surprise that many illustrations of Antarctopelta feature not only nodosaurian dermal armors but pectoral horns. The horns that are shown in this manner are often more ornamental in appearance. The angles at which the horns extend is nearly completely vertical rather than extending in a manner that would allow for their use as offensive weaponry. In this more vertical orientation they would serve more as a deterrent if they were not entirely ornamental. Dermal scutes, like those shown, were also typical in nodosaurian armor schemes. Overall the interpretations of Antarctopelta that are available are typical of many nodosaurians; this is a result of the fragmentary remains that have been attributed to the dinosaur so far.
©"Green Mamba" (website unknown) |
07 June 2016
One Island
James Ross Island is the only site from which Antarctopelta remains have been recovered. Those remains are fragmentary and have been reported in the single description as line drawings of the individual elements of the ankylosaur. Salgado and Gasparini do not expressly mention why there are only line drawings in manuscript. The remains that exist and have been described are characteristic of ankylosaurs enough that there was little doubt of the diagnosis. Reading the paper and examining the line drawings is the best way to understand the dinosaur this week. Unfortunately, however, none of those remains are so obviously ankylosaurian that they can influence illustrations and interpretations of the dinosaur. Bearing that in mind, as you read the paper, form your own image of Antarctopelta in your mind!
06 June 2016
All the Videos
05 June 2016
Kids Love the Antarctic Shield
Antarctopelta oliveri is known from a small amount of material and there is an equal, maybe even lesser, amount of material online to share with dinosaur enthusiasts of all ages. The best site is About, as usual with dinosaur fact pages. Using Wikipedia is definitely an option in this instance that would make sense. There are no videos and very few sites that have anything more information. In the case of animals with little fossil evidence and a mostly inferred body plan this lack of fact pages and videos, as we have seen in the past, is not entirely unusual. Ankylosaurs from Antarctica are unknown other than Antarctopelta, making the minor amount of fossil evidence unique and even more special. The lack of websites is alarming given that information though.
04 June 2016
Antarctopelta Roaming
The small ankykosaur that was shown in yesterday's post was an important part of the South American ecosystem. The animal was not only a prey item for large theropods but also smaller theropods and filled an important niche as an underbrush feeder. Antarctopelta was a short dinosaur and only capable of racing certain levels of vegetation. Some illustrations show the dinosaur reaching up into the lower boughs of trees by bracing itself on tree trunks. This possibility, and other aspects of the anatomy of Antarctopelta, will be investigated during this week.
03 June 2016
Run Carnotaurus
©Ian N. Cost |
©Mohamad Hagani |
©Alvaro Rozalen |
02 June 2016
Classic Popularity
Popularity of theropods among dinosaur fans is usually superficially based on enormous bodies or hideous grotesqueness or some kind of ornamentation. Carnotaurus has all of those things. Some people are intrigued by the horns and other rugosities on the skull and some by the large frame or the rather large mouth. The weirdness of the forelimbs also appears to intrigue many people. The forelimbs we discussed briefly before and throughout we have talked about the big head, big mouth, and big body of Carnotaurus. The dinosaur's horns are very interesting parts of their anatomy. Many of nature's horns and rugosities are embedded in the skin or at least originate from the skin, though there are notable exceptions like horns that are bone. The horns of Carnotaurus are bone and therefore originate from the skull rather than from the skin. Those horns are sometimes flimsy in the best interpretations of Carnotaurus. Are these interpretations of Carnotaurus not the best products of the popularity of the dinosaur, flimsy horns and all?
01 June 2016
Little Arms or Little Wings
I stumbled on Croatian artist Damir G. Martin's depiction of a rather unique Carnotaurus pair. Nowhere that I have seen has the interpretation of the small arms of Carnotaurus included wings and, with the rather well known skin impressions showing scales, feathers have not often (maybe not at all) been discussed in relation to Carnotaurus. The inclusion of feathers, small wings originating from the shortened forelimbs, and the small crest on one individual is interesting as well as novel. These theropods are not running and sprinting quickly, as one paper that we read yesterday asserted, else the feathers would be a bit more ruffled. In this image the feathering appears almost fluffy and certainly very fitting the way these Carnotaurus individuals are standing here.
The wing structures are very avian in this image. However, there are no correlated structures on the fossils like quill knobs on the ulnae. There are also no feather impressions near the arms in the fossils; there are none along the body either of course. The same lack of evidence can be stated for the head structure shown here. A structure like this could also be used, in the illustration, to assume the sex of this individual. After seeing this imagination of Carnotaurus it is almost unfortunate that we have not seen feather evidence in Carnotaurus; it looks like a very fitting (almost turkey-like) rendition of the dinosaur.
The wing structures are very avian in this image. However, there are no correlated structures on the fossils like quill knobs on the ulnae. There are also no feather impressions near the arms in the fossils; there are none along the body either of course. The same lack of evidence can be stated for the head structure shown here. A structure like this could also be used, in the illustration, to assume the sex of this individual. After seeing this imagination of Carnotaurus it is almost unfortunate that we have not seen feather evidence in Carnotaurus; it looks like a very fitting (almost turkey-like) rendition of the dinosaur.
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