Hi All! Welcome to this week’s PaleoNews. Over the past few days, a new hadrosaur from the continent of Appalachia has been discovered (Which I’m very excited about) as well as an antelope who’s nasal anatomy seems to mimic that of hadrosaurian dinosaurs.

NEW FINDINGS 

One of the most interesting findings in the past few days has come out of the examination of the skull of an extinct antelope taxon called Rusingoryx atopocranion. This large, herbivorous mammal hails from the Late Pleistocene of Kenya and bears a nasal dome which may have been able to produce sounds like a trumpet. Incredibly, the ontogeny of Rusingoryx atopocranion bears similarities with that of lambeosaurine dinosaurs. O’Brien et. al. (2016) conclude that because of the similarities between the extinct antelope and lambeosaurs, osseous nasal crests develop only within specific enivronmental, ontogenic, and evolutionary circumstances.

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Rusingoryx atopocranion by the author. Pencils on paper, 2016. 

The past couple of months have been extremely successful for Appalachian paleontology. In the fall of 2015, the presence of leptoceratopsids on Appalachia was announced. Now, a new species of hadrosaurid dinosaur named Eotrachodon sheds light on the probable Appalachian origins for hadrosaurids. Eotrachodon orientalis is known from a partially complete skeleton with an extremely well preserved skull from the Mooreville Chalk Formation of Alabama. During the Cretaceous, Eotrachodon would have roamed around the coast of southwestern Appalachia, likely drinking from the rivers and deltas which ran directly into the Western Interior Seaway. A phylogenetic analysis by Prieto-Marquez et. al. (2016) has found Eotrachodon to be a sister taxon to lambeosaurinae and saurolophinae. The non-saurolophine non-lambeosaurine Hadrosaurus as well as Lophorhothon, a hadrosauroid extremely closely related to the ancestor of hadrosaurids, have been found on Appalachia, it seems likely that the birthplace of hadrosauridae was on the aforementioned landmass.

 

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Appalachian hadrosaurids, like this Hadrosaurus,  suggest that that Appalachia was the birthplace of the hadrosauridae. Artwork by the author. Colored pencils on paper, 2015. 

THE INTERNET AND PALEONTOLOGY

Dodos were incredible animals, but often they are thought of as evolutionary failures or simply just dumb animals. Check out this post at Twilight Beasts detailing these wonderful birds.

At The Bite Stuff, 

At Mark Witton’s Blog, he discusses the giant Deinosuchus and showcases his fantastic  artwork of the giant marine predator. You can find the post here.

At Extinct Monsters, Ben has written two fantastic articles comparing and contrasting the fossil exhibitions of the Perot Museum and the Houston Museum of Natural Science. These post will be especially interesting to those interested in in the aesthetics and scientific impact of museums. You can find the post on the Perot Museum here and the one on the HMNS here.

At SVPOW, you’ll find a couple posts on the evaluation of researchers and the introduction of LWM (Less Wrong Metrics) by Mike Taylor. You can find the posts here, here, here, and here.

At the Royal Tyrell Museum’s blog, they spotlight the newest lecture of their speaker series. Within it, Don Henderson discusses pterosaurs. You can find the post here.

FEATURED FOSSIL 

This week we have a C. megalodon tooth housed within the Stamford Museum’s collections. C. megalodon were massive sharks which preyed on a variety of marine animals, including whales, from the Miocene to the Pliocene epochs of the Neogene period.

IMG_2896

References 

1. O’Brien H. D.; Faith, J. T.; Jenkins, K. E.; Peppe, D. J.; Plummer, T. W.; Jacobs, Z. L.; Li, B.; Joannes-Boyau, R.; Price, G.; Feng, Y.; Tryon, C. A. 2016.”Unexpected Convergent Evolution of Nasal Domes between Pleistocene Bovids and Cretaceous Hadrosaur Dinosaurs.” Current Biology. DOI:10.1016/j.cub.2015.12.050

2. Prieto-Marquez, A.; Erickson, G. M.; Ebersole, J. A. 2016. “A primitive hadrosaurid from southeastern North America and the origin and early evolution of ‘duck-billed’ dinosaurs. “Journal of Vertebrate Paleontology: e1054495. DOI:10.1080/02724634.2015.1054495.

 

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3 thoughts on “PaleoNews #21: Duck-Billed Dinosaurs & The Mammals Which Mimicked Them

  1. I knew that you’d be excited about Eotrachodon. I’m a bit sceptical, though, about the claim that’s been put foward that Appalachia was the birthplace of the hadrosaurs. I remember seeing somewhere that the hadrosaurs are the sister group of the iguanodonts, and both of these groups were descended from creatures like Camptosaurus (you can see a portrait of this animal on my blog). Camptosaurus was a western species, so wouldn’t that mean that the hadrosaurs, or at least their immediate ancestors, originated there?

    A western origin would explain the massive diversification of hadrosaurs in western North America during the late Cretaceous. If the hadrosaurs originated in the east and then migrated westwards fairly late in the game, approx 75 MYA, then we would expect high species diversity among hadrosaurs in the east and significantly low species diversity in the west, since they would not have had enough time to evolve into so many different forms. The fact that there’s a long list of hadrosaur species found in Laramidia and far fewer hadrosaur species found in Appalachia (at least the ones that we know about – there very well could be more which we just haven’t found yet) indicates, at least to me, a western origin for hadrosaurs.

    Of course, if the hadrosaurs did originate in the west, then how did they get to Appalachia? Or vice versa? As you know, the central third of North America was covered in the Western Interior Sea which, at its maximim size, completely cut off western North America from eastern North America. I know that sometime between 80-70 MYA, there was a significant amount of uplift, which caused the sea to drastically retreat. This would give the hadrosaurs on whatever side of the water that they were on a very sort time to radiate outwards and evolve into a whole slew of different shapes and sizes. The time frame seems far too short to allow for this to happen. My only hypothesis is that prior to the splitting of the continent by the Western Interior Sea, hadrosaurs had already appeared and had already populated both sides of North America.

    Actually, I’m far more interested in figuring out how the hadrosaurs, which almost certainly originated somewhere in North America, managed to get to Europe (notably Romania, i.e. Telmatosaurus) and central Asia. Bakker’s idea of land bridges is interesting, but I don’t recall any actual geological findings of a landbridge connecting North America with Asia and the emerging European continent existing approximately 85-75 million years ago. If anything, I thought that sea levels were higher and any land bridges that might have existed beforehand would have been submerged. The reason why Homo sapiens spread around so quickly was due to shrunken sea levels during the Ice Age, but there was no mass shrinkage of the world’s oceans during the late Cretaceous. So how did these dinosaurs manage to simply appear, for lack of a better word, on other continents?

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    1. Hi & thanks for your comment. I’d first like to reply to your thoughts on Appalachia not being the birthplace of hadrosauridae due to the presence of animals like Camptosaurus in the west. Camptosaurus isn’t on the line to hadrosauridae, and is, in fact, not even a hadrosauroid. Rather, it has been shown to be a basal Ankylopollexian, far removed from the hadrosauroid, or even hadrosauriform, family tree. The origin of the hadrosaurids specifically seems to have been in Appalachia because of the presence of species like Hadrosaurus and Eotrachodon which seem to be non-euhadrosaurian hadrosaurs as well as animals like Lophorhothon which sit just outside the hadrosaur family tree. Camptosaurus’s presence in the west doesn’t refute this argument because it isn’t even on the line to hadrosaurs and lived 40 million years before the closest relatives and most basal members of the hadrosauridae.

      Secondly, an Appalachian origin of hadrosaurs explains the wide geographic range of the group much better than a Laramidian origin does. European animals like Telmatosaurus which seem to fall near the base of hadrosauridae have close kin on Appalachia in the form of Lophorhothon and could have migrated to Europe during low sea levels. The ancestors of the more derived hadrosaurids of western North America and Asia could have just as well taken a migratory route across Northern Appalachia during the Turonian Stage of the Late Cretaceous. Here is the link to a page showcasing the extremely well-done maps of Geologist Ron Blakey of North America to help you visualize the landmasses present around Appalachia during the time: http://cpgeosystems.com/nam.html

      I’m not the best one to ask on matters regarding how Asian and European hadrosaurs got to their respective continents. I believe the current consensus is that hadrosaurids went across Alaska and into northern Asia. In the case of the European forms, it seems that they simply island-hopped. You may be able to visualize the process I am explaining better by looking at the maps found at the link above.

      Chase

      Liked by 1 person

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