(C) Lia Booysen |
STL Science Center
31 December 2015
Special Bird
30 December 2015
Extinction Hypotheses
Happy Madagascan children with an Aepyornis egg, (C) Madagascar-tribune |
29 December 2015
Papers for Eggs
Aepyornis papers, as with many aspects of the history that has been documented about these birds, are mostly about eggs. Constituting the most readily available fossil evidence of the birds, these eggs are easily studied because of their abundance. Not all of these egg papers are really about the eggs though. They have to be more specific than many studies because studies that simply describe eggs only really need to be done once. However, describing the calcite orientation in one study and isotope chemistry of the shell in another. Despite a lesser abundance of skeletal remains studies of estimated weight have been published as well. A combination of studying the eggs and the skeleton of Aepyornis culminated, at least once, in a great study of the osteology of embryos that were preserved with eggs. Because we have embryos as well as adults we have a strong line of ontogenetic evidence concerning the bird. Having a great deal of studies from egg to adult is great for any extinct animal and we are extremely lucky to have this much for this animal.
28 December 2015
Young Attenborough
Yesterday's BBC television clips were, when put together, a great short documentary definitely worthy of movie Monday. Instead of searching for a great deal of new documentaries, and there are not all that many that exist, I have decided to share a pair of videos that show just how much David Attenborough loves Aepyornis. There are many reasons that Attenborough has discussed this bird in documentaries decades apart, but he really must have some love for the birds as it has been reported that he kept one of those fossil eggs he had rebuilt while in Madagascar and, as far as the story goes, still has it some 54 years later. In the Zoo Quest to Madagascar show that these come from he also searches for lemurs and other Madagascan animals. However, the important thing is that David Attenborough discusses an egg and shows just how large those eggs were. Also of note is the fact that locals know of egg fragments despite the birds being extinct for a significant amount of time.
27 December 2015
Average Facts, Giant Bird
Elephant Birds appear to be quite popular on the internet. About, Encyclopedia Brittanica, and the BBC all weigh in concisely and with some good images of the bird in question. Many other independent sites also have fact sheets, paragraphs, and even short but detailed descriptions of Aepyornis. The real wealth of Elephant Bird information may be in the short clips below:
On the disappearance of Aepyornis:
On the height of Aepyornis:
On the egg of Aepyornis:
On the extinction of Aepyornis:
On the disappearance of Aepyornis:
On the height of Aepyornis:
On the egg of Aepyornis:
On the extinction of Aepyornis:
26 December 2015
Forgetting Feathers
Image courtesy of Museon; Den Haag, Nederland |
25 December 2015
Christmas Dinner
I skipped yesterday's post because we know most of the reasons that Gastornis is popular and it felt as though it was a post that did not need to be made. Regardless, Happy Christmas (if that is your thing) and Happy Holidays of various other sorts that exist.
This week will be the final fossil bird week to close out the year. I had contemplated discussing one of the oldest extant species of birds, the Magpie Goose (Anseranas semipalmata), but decided to be entirely fossil oriented to close out the bird topic. The fossil bird this week is the genus Aepyornis, a group of extinct ratites endemic to Madagascar. Known colloquially as Elephant Birds, the genus consisted of four species (A. gracilis Monnier 1913; A. hildebrandti Burckhardt 1893; A. maximus I. Geoffroy Saint-Hilaire 1851; and A. medius Milne-Edwards and Grandidier 1866) and is touted as the heaviest group of birds to have ever lived. The largest, A. maximus, is known to have weighed up to 400 kg (880 lbs). This is a known number because Elephant Birds have only been extinct for approximately 1000 years. Being a ratite, and weighing 400 kg, Aepyornis species were not capable of flight, no matter how much they may have wanted to escape Madagascar. Ratites tend to look vaguely like chicks throughout ontogeny, and such "youthful" appearances may have caused early explorers to assume that Aepyornis was not fully grown, even at 400 kilograms. However, use of the name Elephant Bird by many, including Marco Polo, may have actually referenced raptors living on or near Madagascar more than the giant ratites. Despite a confused nomenclature, Elephant Birds are enormous recently extinct ratites, like Moas, that went extinct partially because of human interaction (i.e. hunting). Considering an Aepyornis egg was large enough to feed a small family hunting the animals to extinction does not seem very far-fetched at all.
This week will be the final fossil bird week to close out the year. I had contemplated discussing one of the oldest extant species of birds, the Magpie Goose (Anseranas semipalmata), but decided to be entirely fossil oriented to close out the bird topic. The fossil bird this week is the genus Aepyornis, a group of extinct ratites endemic to Madagascar. Known colloquially as Elephant Birds, the genus consisted of four species (A. gracilis Monnier 1913; A. hildebrandti Burckhardt 1893; A. maximus I. Geoffroy Saint-Hilaire 1851; and A. medius Milne-Edwards and Grandidier 1866) and is touted as the heaviest group of birds to have ever lived. The largest, A. maximus, is known to have weighed up to 400 kg (880 lbs). This is a known number because Elephant Birds have only been extinct for approximately 1000 years. Being a ratite, and weighing 400 kg, Aepyornis species were not capable of flight, no matter how much they may have wanted to escape Madagascar. Ratites tend to look vaguely like chicks throughout ontogeny, and such "youthful" appearances may have caused early explorers to assume that Aepyornis was not fully grown, even at 400 kilograms. However, use of the name Elephant Bird by many, including Marco Polo, may have actually referenced raptors living on or near Madagascar more than the giant ratites. Despite a confused nomenclature, Elephant Birds are enormous recently extinct ratites, like Moas, that went extinct partially because of human interaction (i.e. hunting). Considering an Aepyornis egg was large enough to feed a small family hunting the animals to extinction does not seem very far-fetched at all.
Left to right: Aepyornis maximus, Struthio camelus, Homo sapiens |
23 December 2015
More Anatomy
Compiled by Adam Pritchard and Matt Borths of the Past Time podcast |
22 December 2015
Use It To Crunch Seeds
Evidence has mounted that Gastornis was not a carnivore a great deal since it was originally covered in this blog. Back in 2012 when we originally discussed the diet of the giant bird and share all kinds of illustrations and clips from the Walking With series, meat was the only thing considered to be on the menu for Gastornis. Since that time biomechanical studies from earlier have been countered by evidence from chemical analyses that show that the diets of these birds were most likely highlighted by vegetable matter. When we look at the beak both possibilities obviously make sense. The Witmer and Rose biomechanical study asserted that the beak was strong enough to break bones and certainly to kill small animals like Eohippus. They are not incorrect and the implications that they made regarding diet are logical, especially for a bird that appears to be extremely convergent with South American terror birds. However, that power could have also been used to break open tough seeds and their meat inside. The large beak appears to have been mostly flattened in the oral cavity (the roof of the oral cavity or the ventral shelf of the premaxilla and maxilla), which is good for crushing, but not entirely ideal for breaking seeds open in the most efficient manner. What could be more efficient for this purpose may be considered coincidental or may have been lost in fossilization. The anatomical character that we are considering here could be a ridge or sharp edge to the beak that was keratinized for added strength. Assuming that this was not lost and may not have existed (I have not seen the fossils first hand and cannot therefore assert to its existence or loss) another option to make the breaking open of seeds more efficient, is occlusion of the upper beak that we have discussed many times with the lower beak or mandible (dentary, splenial, angular, and surangular). This occlusion can be seen, but is minimal between the beak and mandibles. It can be assumed from these bones that the keratin ramphotheca covering the beak would not have occluded differently, but we cannot say that they did not have sharp edges capable of shearing seeds. Given all of the papers and anatomical evidence, it seems that we could consider Gastornis more of a terror to seeds, than other animals.
21 December 2015
The Proposed Diet
20 December 2015
Giant Facts, Giant Bird
The revelation from yesterday that Gastornis is an enormous duck should have sunk in quite well by now. If it has not, here are some interesting facts about that giant duck. The first fact pages come from the BBC which chose Gastornis as a key figure in the Walking With Prehistoric Beasts series that appeared after the dinosaur series. That version of Gastornis was well done; however, they did imply that the hatchet-like movement of the beak was basically the same mechanism used by other large birds that lived, rather than noting the lack of a known hook on the premaxilla. The page hosted by Dinosaur Jungle does not worry about this hook-and-hatchet conundrum and instead simply discusses the facts that are know about Gastornis. Intriguingly, the image used on the page makes Gastornis look much more like a giant walking eagle and a great deal less like a duck relative; we do not expect it to look like a duck exactly, despite how much we have mentioned that it is related to ducks and geese. Of perhaps the most interest today, is an entry in Brian Switek's National Geographic blog Laelaps which introduces the idea that the bill of Gastornis was constructed for a more herbivorous diet than a fleshy diet. I must highly recommend reading this as an introduction to the topic of diet that we will discuss in the next couple of days. The last time Gastornis appeared in this blog we accepted the predatory role, and it was mentioned heavily in yesterday's entry also, but we will explore other uses of the morphology of the bill that we have been very actively discussing this weekend so far.
19 December 2015
Well Known Birds
Gastornis with Titanis inset |
18 December 2015
Previously Viewed Gaston's Bird
From a paper by Matthew, W. D., Granger, W.,and Stein, W. 1917. |
17 December 2015
Sometimes It Is
Popularity because of popularity sounds funny, but it is a theme that has been addressed here many times before. Perhaps too many time in fact. The fact with fossil animals, though, is that sometimes they are famous just for being famous. The penguins discussed this week fall into that exact category as nothing makes them exceptionally famous except that they are well known for being giant fossil penguins. To anatomists and ornithologists they are amazing specimens of the early radiation and specialization of the penguin family. They are testaments to the anatomical organization of penguins in that they provide us with a first indication of anatomy that is still readily employed by extant penguins; adaptations that have changed little in 36 million years are obviously well situated to working in the role and environments in which they are employed. Regardless of how they are touted, both of these animals were indeed kings of the water in their day, in the bird world. They remain important and amazing in our view today.
16 December 2015
Fossil Collections
From Clarke, et al. 2008 |
- 1.- Clarke JA, et al. 2007. Paleogene equatorial penguins challenge the proposed relationship between biogeography, diversity, and Cenozoic climate change. PNAS 104 (28): 11545-11550.
- 2.- Clarke JA, et al. 2010. Fossil Evidence for Evolution of the Shape and Color of Penguin Feathers. Science 330 (6006): 954-957.
- 3.- Ksepka DT and Ando T. 2011. Penguins Past, Present, and Future: Trends in the Evolution of the Sphenisciformes; del libro “Living Dinosaurs: The Evolutionary History of Modern Birds”, editorial John Wiley & Sons.
15 December 2015
Black and White Print, Not Feathers
The most important thing to remember about these fossil penguins is that they are very much like modern penguins. That fact born in mind, reading the papers detailing studies of these penguins makes the papers easier to feel okay about. Not understanding that these penguins are like modern penguins in many regards make the papers seem very odd, as they discuss the animals in ways that make them seem quite modern in respect to the "oddness" of other fossil animals in comparison to their extant descendants. After reading the papers this logic makes sense, I promise. Those papers detail the evolutionary history of penguins as well as detailing individual aspects of both penguins. Those include osteology and the colors of feathers. Fossil feathers and coloration is a fantastic topic actually, and I definitely recommend reading that last paper on Inkayacu.
From Clarke, et al. 2010. |
14 December 2015
Penguins in History
Yesterday I shared videos for both Inkayacu and Icadyptes. Somehow, despite the fact that penguins are probably the neatest flightless birds, there are not more stories and videos devoted to these two ancient penguins. It is both sad and great that we do not really need a video concerning these two penguins directly to know how they fed, their mode of locomotion, or what they looked like. The two penguins were both penguin-like in appearance and most likely swam the same way that extant modern penguins swim. The feeding done while swimming, of course, was probably also similar if not identical. The depth at which that feeding was done in each genus was probably much different though. Due to the fact that extant penguins provide a good hypothetical proxy for these fossil penguins, please enjoy this wonderful ballet of penguins swimming, doing dopey things, and generally being penguins.
13 December 2015
Penguin Facts
Sharing facts for two animals today is best done in a list format. Therefore, please attend to the following lists!
Inkayacu:
About: http://dinosaurs.about.com/od/prehistoricbirds/p/Inkayacu.htm
Interview with Dr. Julia Clarke:
Icadyptes:
About: http://dinosaurs.about.com/od/prehistoricbirds/p/giant-penguin.htm
Animal A Day: http://animaladay.blogspot.com/2012/11/icadyptes-salasi.html
Dr. Rodolfo Salas showing fossils and an interview with Dr. Mario Urbina:
Inkayacu:
About: http://dinosaurs.about.com/od/prehistoricbirds/p/Inkayacu.htm
Interview with Dr. Julia Clarke:
Icadyptes:
About: http://dinosaurs.about.com/od/prehistoricbirds/p/giant-penguin.htm
Animal A Day: http://animaladay.blogspot.com/2012/11/icadyptes-salasi.html
12 December 2015
Penguins Competing for Space
Icadyptes; (C) Nobu Tamura |
Unattributed |
11 December 2015
Dueling Penguins
Icadyptes (top) and Inkayacu (bottom) |
10 December 2015
How Does One Become Famous?
The greatest toys I have seen (toys always relate to popularity in, I am sure, some mathematical way) of Jeholornis are actually quite interesting in their own right. These range from stuffed animals (see below) to styrofoam flyers to full on sculpture. I have to admit that the sculpture is amazing. There is a great deal of painstaking detail in that piece and I am quite impressed with it; I would own it if I could and I had a place for it. Jeholornis has occupied our imaginations and entertained our fancies about the origin of birds, and that is probably, in part, why it is such a popular early bird. The fact that it is an early bird has a lot to do with its popularity in the realm of paleontology. There is even a book (dedicated to all Jehol fossils really) that deals extensively with little dino-bird. It may be worth picking up, but as with any scientific book, it is difficult to find for a reasonable price.
09 December 2015
Forgotten Yesterday
(C) Matt Martyniuk |
The claws on the wings of Jeholornis are also of great interest. One of the age old questions surrounding birds is when did the hands change such that they no longer ended in claws, but only phalanges supporting feathers? As more and more fossil birds come to light the timeline of clawlessness becomes slightly clearer. It may not ever be definitively known when clawed wings gave way completely to feather only wings, but it would be interesting to discover. The claws of Jeholornis are fairly small and appear almost as an afterthought of development, but even this appearance does not make the phylogeny of clawed wings distinctly clearer. Regardless, Jeholornis is a small bird that still resembles a dinosaur in many ways and has, through a bit of luck, been preserved in significant numbers in the fine sediments of the Hebei Province.
08 December 2015
Slabs for Writing
The preservation of exquisitely fragile animals like birds (and pterosaurs, silly flying animals) is usually done with such fine sediments that the fossils are often found and removed as slabs of material. After those slabs are opened there is typically a slab, holding the actual fossil, and a counterslab that holds an impression of the fossil; this is where our wonderful feather impressions are most often found, though they have been known to come from the slab containing the fossil as well. Many of the remains of Jeholornis that have been procured, and certainly the ones that have been described, are found in this kind of arrangement. This is the reason also that so many of those papers are wonderfully descriptive and have such beautiful, for a crushed fossil bird, images of the fossil remains that are being described at the time. These include comparison papers between birds (Archaeopteryx vs. Jeholornis) as well as the straight descriptions of Jeholornis.
07 December 2015
Using up the Documentaries
Yesterday I shared a video that was probably the best video that is easy to get to online featuring Jeholornis; it was a clip from Dinosaur Train which may make it seem a little sad. However, there is also a hybrid edited video that an internet denizen put together on Jeholornis. It may actually feature another animal in some parts of it, but that is okay, as it is done fairly well and shows a very similar animal if nothing else. Watch it and let us know what you think about it:
The animal that comes from the BBC clips is undoubtedly a different early/near bird, but I cannot place it for one reason or another and it would be wonderful to get a memory boost!
06 December 2015
Too Much Fame
Jeholornis is so well known in the public domain that finding simple fact files or short essays describing the small primitive bird is actually quite difficult. The problem is that there are just too many links online. Some of the quick and simple pages that stand out right away come from About and the Encyclopedia of Life. The article from the EoL is not much edited from the original Wikipedia article, but it is still worth reading. Jeholornis has even shown up everywhere in videos, meaning that we can look to videos as well to learn about this bird. There are not any that I recommend above others, but there is a good episode of Dinosaur Train in which Jeholornis features prominently. I would certainly recommend watching it with the little paleontologists in your life today! You can find that video at this link.
05 December 2015
Flying and Chasing
(C) Emily Willoughby |
04 December 2015
Long Tails and Little Teeth
The bird from Jehol, a region in China (now Hebei Province), was turkey sized and capable of powered flight. Despite having teeth Jeholornis had a diet consisting of mostly seeds. Their long tails, however, were used for flight, and were therefore much more bird-like than their teeth. Regardless, the main attraction of Jeholornis was neither its long tail nor its mouth that contained small teeth. Their claim to fame was is their clear flight abilities and the fact that that powered flight was achieved with well preserved feathers. Those feathers are asymmetrical, an important adaptation in powered flight.The other important characteristic associated with Jeholornis is the shear number of specimens and the variety that may (only seven have been described) be preserved in those specimens is a very intriguing and important for the history of birds. This week's bird is also quite beautiful, as far as delicate bird fossils go.
From O'Connor, et al. 2013 |
03 December 2015
Like an Ostrich of Doom
Whenever a bird is popular, or any fossil animal for that matter, it is always fun to look at extant birds to see what kind of similarities there are in the two popular taxa. Terror birds in general are most reminiscent of ostriches and other ratites. What we really care about on Thursday is the popularity of the animal and whether or not there is evidence of that popularity out in the wide world. We know, with the television, improvised cards for games like YuGi-oh, and even the creation of video game characters (we have not seen a good Spore creature in a while). Titanis is a very popular bird and, being the only terror bird from North America, it is quite unique. Also, look at this hypothetical baby, he is adorable:
02 December 2015
Strange Ideas
There was a hypothesis once that Titanis, and other Phorusrhacids, may have had a theropod-like claws at the end of their wings. This hypothesis came to light because the writs was considered to be extremely rigid and supposedly lacked the ability to fold against the body like a traditional wing. However, extant "terror birds", the seriemas of South America, do not possess a clawed manus at the end of their wings despite a largely unchanged wing and wrist. In fact, looking at a seriema is in a way looking at a scaled down, though no less vicious, version of their ancestors of the past. These living birds possess short wings and elect to fly-hop when they do leave the ground, which is rare. The idea that Titanis may have had wings weak enough to restrict flight but strong enough to allow for fly-hopping to slightly higher structures makes the speedy predator slightly more frightening as it adds a vertical component to its domain. Aside from obstacle avoidance, such an ability would have probably been most useful in nesting habits and, though its weight would have likely been too much for a typical branch, the bird could have built enormous nests that required fly-hopping to gain the apex of. The idea of a bird that large flying even an insignificant distance vertically is nearly preposterous though, and in all likelihood Titanis never left the ground on purpose. Regardless, the North American terror bird was more than capable of inflicting damage on prey items without clawed hands or the ability to chase other animals into trees.
01 December 2015
Titanic Research
A great deal of research has been conducted regarding Titanis walleri over the years. The bird's body has been discussed many times over for many different reasons, but mostly for descriptions of the known skeleton and its relationship to other Phorusrhacids. Beyond descriptions many have studied the age of the birds and their genus. Some of the most cursory treatments of the bird are actually references in papers on the "Great American Interchange" that occurred when South American and North America came into contact with one another for the first time.
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