Dromaeosaurids, tyrannosauroids, and a new website: late spring and summer 2018 at an Odyssey of Time

Hello everyone! I’m sorry I haven’t posted for a while, but I’ve been researching away on some exciting new discoveries! I do, however, want to share some of the recent highlights of my work.

A giant tyrannosaur from the Cenomanian

In March, my manuscript on a huge partial theropod metatarsal from ~95 million-year-old sediments in New Jersey was published in the Bulletin of the Yale Peabody Museum of Natural History (Brownstein, 2018a). Although the find is admittedly very fragmentary, it shares many features with the metatarsals of intermediate-grade tyrannosaurs like Appalachiosaurus and clades out nearby that taxon in a phylogeny of Tyrannosauroidea. The fossil is the first bone of a tyrannosaur reported from the Potomac Formation and the oldest known eastern North American occurrence of the clade.

Even more interestingly, the fossil shows tyrannosaurid-line tyrannosaurs had already achieved sizes of 6 or more meters during the Cenomanian, contrary to research on geologically younger Asian representatives of the group which has suggested a later date for the development of gigantism (e.g., Brusatte et al. 2016).

The Potomac tyrannosaur. Photo by the author, 2017. 

The large dromaeosaurs of North Carolina

I also published on a large theropod tooth from the little known Clifton Farm site (Brownstein, 2018b), which also produced a possible ceratopsian maxilla described by Longrich (2016). A look at the morphology of the denticles of the tooth and inclusion of the specimen in a couple principle components analyses allow for its identification as the crown of a large dromaeosaurid, perhaps one slightly larger than Deinonychus. Here’s the catch: the tooth is from the Campanian, when very few mid-sized dromaeosaurids are known. Furthermore, the tooth is unlike any dromaeosaurid crown previously described from the southeastern US, suggesting there’s evidence for the existence of at least two species in the Campanian of southern Appalachia.

Theropod bones with feeding traces.

The most publicized of my recent papers came out in early June (Brownstein, 2018c). In it, I described two interesting theropod dinosaur limb bones from New Jersey in the collections of the Yale Peabody Museum. One had a number of pits (probably made by crocodyliforms) that caught my eye upon initially seeing the bone in a drawer with other eastern North American dinosaur bones. In addition, the bone seems to show evidence of invertebrate activity on its surface. A closer look at a partial ornithomimosaur femur revealed scores likely made by sharks. Both bones demonstrate the complex ecological interactions that were happening off the coast of eastern North America during the seven million years or so before the K-Pg extinction.

Ellisdale

A large dromaeosaurid tooth from Ellisdale. Photo by the author, 2017.

I’m very excited to share that just today my paper on theropod dinosaur material from the Ellisdale site was published in the Journal of Paleontology. Although this highly fossiliferous locality was first discovered in 1980, no comprehensive description of any dinosaur material collected from it has previously been published. I identified the presence of several theropod clades on the basis of teeth and isolated limb material. Teeth at the site are referable to a number of different animals, including a very large dromaeosaurid, a smaller maniraptoran, and tyrannosauroids similar to Dryptosaurus and Appalachiosaurus. You can read the full paper, which was kindly made freely open-access by the journal, here.

New website

Today, I also finished making the final touches on my new website (chasebrownstein.wordpress.com). Here you can view my publications, summaries of my research projects, and notes on other science-related things I’ve been up to.

Overall, it’s been a productive, exciting spring and summer. As the academic year comes on the horizon, I’ll try to start blogging more again. Some very exciting projects are in the works, so please watch this space!

References.

Brownstein, C.D. (2018). Tyrannosauroid from the lower Cenomanian of New Jersey and its evolutionary and biogeographic implications. Bulletin of the Peabody Museum of Natural History 59(1):95–104. DOI: https://doi.org/10.3374/014.058.0210

Brownstein, C.D. (2018). A large dromaeosaurid from North Carolina. Cretaceous Research 92:1—7. DOI: https://doi.org/10.1016/j.cretres.2018.07.006

Brownstein, C.D. (2018). Trace fossils on dinosaur bones reveal ecosystem dynamics along the coast of eastern North America during the latest Cretaceous. PeerJ 6:e4973 (23 pp.). DOI: https://doi.org/10.7717/peerj.4973

Brownstein, C.D. 2018. The distinctive theropod assemblage of the Ellisdale site of New Jersey and its implications for North American dinosaur ecology and evolution during the Cretaceous. Journal of Paleontology 92(5): in press. 

 

 

 

Paper Published: Appalachian Dinosaur Biogeography and Ecology

After four years of research, I am very pleased to announce that my paper reviewing all known Appalachian dinosaur faunas and analyzing Appalachian dinosaur biogeography and ecology was published in the journal Paleontologia Electronica (Brownstein, 2018). As usual, I will give an overview of the paper on this website.

In the past several years, we’ve learned a considerable amount about many aspects of Laramidian dinosaur biology, including their ecology, evolutionary relationships, and distribution. Such research has manifested in papers like Lehman (1997), Gates et al. (2010), Sampson et al. (2010), Gates et al. (2012), Sampson et al. (2013), etc. However, a major gap has persisted in the data, stemming from the poorly-documented fossil record east of the American Interior.

The new paper, which systematically reviews the dinosaurs of each fauna known from eastern North America and compares them using the Simpson similarity index, Jaccard coefficient, and Jaccard distance (e.g., Jaccard, 1902; Simpson, 1943), was written by me with the intention of helping to alleviate this issue.

My analyses seem to suggest several points about Appalachian dinosaur genera. Firstly, the data suggest that Appalachian dinosaurs represented relict forms surviving in isolation, an often-proposed hypothesis (Denton and O’Neill, 1995, 1998; Schwimmer, 1997; Kiernan and Schwimmer, 2004). Additionally, dinosaur provincialism on Appalachia seems to (maybe) be a thing, something proposed by Schwimmer (2016). Finally, competition between predatory dinosaurs and large crocodylians is also discussed, a topic that has actually attracted quite a lot of attention that has resulted in several extensive pieces of literature (e.g., Gallagher, 1995; Schwimmer, 2002; Noto et al., 2012).

I’d like to extend my utmost gratitude to all the researchers who provided me with information for this project and to everyone at PE for their helpfulness in getting this piece of research out there.

Refs.-

1. Brownstein, CD. 2018. The biogeography and ecology of the Cretaceous non-avian dinosaurs of Appalachia. Paleontologia Electronica 21.1.5A: 1-56. DOI: https://doi.org/10.26879/801
2. Lehman TM. 1997. Late Campanian dinosaur biogeography in the western interior of North America, p. 223-240. In: Wolberg D, Stump E, eds: Dinofest International Proceedings. Philadelphia Academy of Natural Sciences, Philadelphia,  USA.
3. Gates TA, Sampson SD, Zanno, LE, Roberts, EM, Eaton, JG, Nydam RL, Hutchison JH, Smith JA, Loewen MA, Getty MA. 2010. Biogeography of terrestrial and freshwater vertebrates from the Late Cretaceous (Campanian) Western Interior of North America. Palaeogeography, Palaeoclimatology, Palaeoecology 291:371-387. https://doi.org/10.1016/j.palaeo.2010.03.008
4. Sampson SD, Loewen MA, Farke AA, Roberts EM, Forster CA, Smith JA, Titus AL. 2010. New horned dinosaurs from Utah provide evidence for intracontinental dinosaur endemism. PLoS ONE 5(9):e12292.
5. Gates TA, Prieto-Márquez A, Zanno LE. 2012. Mountain building triggered Late Cretaceous North American megaherbivore dinosaur radiation. PLoS ONE 7(8):e42135. https://doi.org/10.1371/journal.pone.0042135
6. Sampson SD, Loewen MA, Roberts EM, Getty MA. 2013. A new macrovertebrate assemblage from the Late Cretaceous (Campanian) of southern Utah, p. 599-617. In: Titus AL, Loewen MA, eds: At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah. Indiana University Press, Bloomington, USA.
7. Jaccard P. 1902. Lois de distribution florale. Bulletin de la Socíeté Vaudoise des Sciences Naturelles 38:67-130.
8. Simpson GG. 1943. Mammals and the nature of continents. American Journal of Science 241:1-31.
9. Schwimmer DR. 1997. Late Cretaceous dinosaurs in Eastern USA: A taphonomic and biogeographic model of occurrences, p. 203-211. In: Wolberg E, Stump E, eds: Dinofest International Proceedings. Philadelphia Academy of Natural Sciences, Philadelphia, USA.
10. Denton RK, O’Neill RC. 1995. Prototeius stageri, gen. et sp. nov., a new teiid lizard from the Upper Cretaceous Marshalltown Formation of New Jersey, with a preliminary phylogenetic revision of the Teiidae. Journal of Vertebrate Paleontology 15(2):235-253.
11. Denton RK, O’Neill RC. 1998. Parrisia neocesariensis, a new batrachosauroidid salamander and other amphibians from the Campanian of eastern North America. Journal of Vertebrate Paleontology 18(3):484–494.
12. Schwimmer DR. 2016. Was there a southeastern dinosaur province in the Late Cretaceous?. Geological Society of America Abstracts with Programs 48(3):22-23.
13. Gallagher WB. 1995. Evidence of juvenile dinosaurs and dinosaurian growth stages in the Late Cretaceous deposits of the Atlantic Coastal Plain. Bulletin of the New Jersey Academy of Science 40:5-8.
14. Schwimmer DR. 2002. King of the Crocodylians: The Paleobiology of Deinosuchus. Indiana University Press, Bloomington, USA.
15. Noto CR, Main DJ, Drumheller, SK. 2012. Feeding traces and paleobiology of a Cretaceous (Cenomanian) crocodyliform: Example from the Woodbine Formation of Texas. Palaios 27(2):1-11.

Preprint Published: Tyrannosaur brains from the eastern US

Hi all! Just a little update here on my research. Yesterday, a preprint of mine (Brownstein, 2018) describing the first piece of a theropod braincase known from the Late Cretaceous of New Jersey was published at PeerJ Preprints. What follows is a little summary of the research.

As you all know, the fossil record of terrestrial animals from the Cretaceous of North America is poor, especially when compared to that of the American West. Nevertheless, recent discoveries have allowed us to fill in some of the gaps regarding eastern North American dinosaurs. One such gap is our record of dinosaur cranial material from the eastern United States. Material from the skulls of dinosaurs is super rare in this area, and so any chunk can potentially tell us a lot about eastern North American dinosaur anatomy and evolution.

One such specimen is the possible partial prootic (a bone on the side of the braincase) of a juvenile tyrannosauroid dinosaur collected in the mid-1990s from the Ellisdale site of New Jersey. The bone is actually in pretty good condition. The unfused sutures on all sides of the specimen and the prootic’s small size suggest it belonged to a juvenile animal, thus representing one of the few immature dinosaur specimens from northeastern North America.

The prootic in question.

The prootic can tell us several things about eastern North American dinosaurs, including that their braincases were similar in several ways to those of mid-Cretaceous tyrannosauroids from Asia like Timurlengia (Brusatte et al., 2016). The morphology of the prootic overall supports the notion that Appalachian tyrannosauroids were evolutionarily somewhere between the Tyrannosauridae and the basal tyrannosauroids of the Jurassic and Early Cretaceous.

Stay tuned for more, and thanks for reading!

References.

Brownstein CD. (2018) Prootic anatomy of a juvenile tyrannosauroid from New Jersey and its implications for the morphology and evolution of the tyrannosauroid braincase. PeerJ Preprints6:e26467v1 https://doi.org/10.7287/peerj.preprints.26467v1

Brusatte SL, Averianov A, Sues HD, Muir A, Butler IB. 2016. New tyrannosaur from the mid-Cretaceous of Uzbekistan clarifies evolution of giant body sizes and advanced senses in tyrant dinosaurs. Proceedings of the National Academy of Sciences of the United States of America 113(13):3447–3452

 

 

Antediluvian Realms of the East: the Tar Heel and Coachman Formations

Morning, and the orange and beige of a celestial titan rising through slivers of cloud coat the swampy landscape with a buzzing, ochre light. Gently sloping mountains in the far distance, each decorated in a single shade of green trees, are the first to grasp at the brightest rays of light from the sun. Giant azhdarchid pterosaurs, drowsy and chilled by the morning air, launch off of their craggy towers in the highlands to search for food in the swamps and marshes. Within a few minutes, they reach the sky above the lowlands and sink down towards waterways beckoning with a biological buffet. The loud morning calls of ancient insects, amphibians, reptiles, and birds illuminate a scene exclusive to the Campanian. The azhdarchids land by the side of a waterhole, already taking notice of some of their company in these marshes. Nearby, a small, rough-skinned leptoceratopsid rips off leaves from some low foliage as it grunts at a small lizard picking up droppings from the dinosaur’s morning feast. This sturdy dinosaur is related to the massive ceratopsids of the west, though here it lies in the shadows of other dinosaur species. The grey and aquamarine leptoceratopsid, taking notice of the azhdarchids, sniffs and scurries into the underbrush. 

Nearby, a flock of ornithomimosaurs stops to drink in the early morning sun. Brilliantly adorned in gleaming black, blue, and grey feathers, the ostrich-mimic dinosaurs huddle close together as they hydrate for the day ahead. Two males, both decked out in feathers designed to impress the females of the crowd, start to kick and peck at each other while displaying the brilliant patterns that spur from their forelimbs. Both males are soon driven off when a mixed heard of Lophorhothon and Hadrosaurus arrive by the side of the waterhole. At 8-9 meters in length, these are all medium-sized hadrosaurs, the Lophorhothon representing a more ancient lineage of duckbills than their Hadrosaurus companions. As the large herbivores lower their heads to drink, Saurornitholestes dromaeosaurs scamper out from their feet. These small predators would do well to mind the size and temper of the hadrosaurs. 

On the opposite side of the waterhole, a herd of true giants triumphantly marches out from the surrounding swamps and bayous. These are Hypsibema crassicauda, 15 meters long and 15 tons in weight, the largest animals of these lands. The herd of hadrosaurs, thirteen strong, lumbers toward the edge of the waterhole to drink. The massive skulls of the titans slowly gulp up the water as smaller dinosaurs and crocodylomorphs flee the scene. A large female Dryptosaurus, 9 meters from head to tail, is also deterred from a quick stop for water by the Hypsibema herd. Several fresh water turtles push themselves back into the murky water. 

Back on the other side of the waterhole, a disturbance spooks the hadrosaurs. Suddenly, an ornithomimosaur is pulled underneath the water. Just off of shore, the head a giant Deinosuchus crocodyliform emerges as the massive predator tries to gulp down the dead ornithomimosaur whole. The azhdarchids take off. They’ve had enough of the lowlands. 

For the majority of the 19th and 20th centuries, the Cretaceous animals of the Carolinas have remained obscure, with decades lacking in finds punctuated by tantalizing glimpses of Cretaceous Carolinian ecosystems by means of fragmentary specimens. Ebenezer Emmons, namer of the Adirondack mountains, described isolated teeth that would later be identified as those of the massive crocodylian Deinosuchus rugosus (e.g., Emmons, 1858; Schwimmer, 2002), an noted paleontologist Edward Drinker Cope designated hadrosaur remains from a marl pit in North Carolina as the type of Hypsibema crassicauda 11 years later (Cope, 1869).

However, the past forty years have seen revelations in our understanding of the Cretaceous species of these states, including the publication of several Cretaceous-age faunas from sites within them. New discoveries of terrestrial and aquatic vertebrates from the Carolinas have illuminated several biogeographic trends from the Cretaceous of North America, supporting the notion that Appalachia was a refugium for certain vertebrate groups like as non-tyrannosaurid tyrannosauroid and basal hadrosauroid dinosaurs.

In North Carolina, perhaps the most important (in terms of terrestrial fossils) site is Phoebus Landing, a tidal-estuarine deposit located near Elizabethtown (e.g., Miller, 1967; Baird and Horner, 1979; Weishampel and Young, 1996). This site, bearing sediments of the middle-late Campanian Tar Heel Formation (e.g., Baird and Horner, 1979; Weishampel and Young, 1996; Weishampel et al., 2004; Self-Trail et al., 2004; Schwimmer et al., 2015), has not only produced skeletal elements from at least four different dinosaur species, but has also preserved teeth and bones from the massive crocodylian Deinosuchus. Among the dinosaur remains discovered here are the morphologically odd (NB: distinct from adult H. foulkii) massively constructed vertebrae of the giant (12+ meter long) hadrosauroid Hypsibema crassicauda (e.g., Baird and Horner, 1979; Weishampel and Young, 1996). Additional evidence of supermassive hadrosauroids in the Tar Heel Formation ecosystem comes in the form of a massive partial humerus only outsized by that of Magnapaulia from Phoebus Landing (Baird and Horner, 1979). Unfortunately, the fragmentary nature of these specimens means that, for now, only tantalizing glimpses of the Cretaceous giants that must have once roamed the Carolinas have been afforded by the marls. Specimens comparable to the corresponding elements in Hadrosaurus foulkii have also been recovered from the sediments at Phoebus Landing (e.g., Baird and Horner, 1979; Weishampel and Young, 1996), and Miller (1967) suggested the presence of “Hadrosaurus minor” (a dubious species of New Jersey hadrosaur possibly representative of juveniles of indeterminate genera) in the fauna present at the site. Finally, specimens comparable to the hadrosauroid Lophorhothon atopus have been recovered (e.g., Baird and Horner, 1979; Weishampel and Young, 1996). From all of this, it seems safe to conclude that two to three species of hadrosaurid were present in the Tar Heel fauna at Phoebus Landing. Importantly, a partial jawbone from a site nearby Phoebus Landing was recently described as Appalachia’s first neoceratopsian (Longrich, 2016).

Fossils from Phoebus Landing were probably deposited in a tidal or estuarine setting. Photo by the author, 2017. 

 

Theropods also left an important record at Phoebus Landing. Teeth and hindlimb elements possibly referable to Dryptosaurus aquilunguis have been recovered and described from the site, as have ornithomimosaur bones and dromaeosaurid teeth (e.g., Miller, 1967; Baird and Horner, 1979; Weishampel and Young, 1996; Kiernan and Schwimmer, 2004). Along with the data from ornithischian remains, the Tar Heel supported at least seven different dinosaur genera.

Lophorhothon and other hadrosauroids from the Tar Heel Formation were probably similar in form to Claosaurus (above). Photo by the author, 2017. 

Of overlapping time and geographically adjacent to the Tar Heel Formation is Coachman Formation, which in South Carolina has recently been found to contain several species of dinosaur. Schwimmer et al. (2015), in their extensive review of several sites with Coachman Formation outcrops, described remains assignable to the tyrannosauroid Appalachiosaurus montgomeriensis, the dromaeosaurid Saurornitholestes langstoni, at least one additional dromaeosaurid represented by teeth, indeterminate ornithomimosaurs, indeterminate maniraptorans, specimens comparable to “hadrosaurines”, and indeterminate hadrosauroid and ornithischian material. In addition, many species of turtles, fish, and crocodylians (including Deinosuchus) were described by Schwimmer et al. (2015) from Coachman Formation sediments, further bettering our understanding of that ecosystem.

The dromaeosaurid Saurornitholestes would have been similar to Velociraptor (skull imaged above). Photo by the author, 2015. 

 

The Tar Heel and Coachman Formations represent important glimpses of Cretaceous life in the Carolinas that are becoming clearer with new research into their faunas. The formations’ geographic location, sandwiched between the historically notable fossiliferous formations of New Jersey and Delaware and the more recently recognized ones of the states of Alabama, Mississippi, Tennessee, Missouri, and Georgia, mean the faunas of the Tar Heel and Coachman are essential to our understanding of the biogeography of vertebrates on Appalachia. What remains to be discovered in these deposits will certainly reveal more and more about the life forms of the obscure landmass that sat east of the Western Interior Seaway over 68 million years ago.

For more on some of the dinosaurs of the Tar Heel and Coachman Formations, see these previous posts:

Antediluvian Beasts of the East: Hypsibema crassicauda

Antediluvian Beasts of the East: Dryptosaurus aquilunguis 

PaleoNews #18

References.

Schwimmer DR. 2002. King of the Crocodylians: the Paleobiology of Deinosuchus. Bloomington: Indiana University Press.

Cope ED. 1869. Remarks on Eschrichtius polyporus, Hypsibema crassicauda, Hadrosaurus tripos, and Polydectes biturgidus. Proceedings of the Academy of Natural Sciences of Philadelphia 21:191-192.

Miller HW. 1967. Cretaceous Vertebrates from Phoebus Landing, North Carolina. Proceedings of the Academy of Natural Sciences of Philadelphia 119:219-239.

Baird D and Horner JR. 1979. Cretaceous dinosaurs of North Carolina. Brimleyana 2:1-28.

Weishampel DB and Young L. 1996. Dinosaurs of the East Coast. Baltimore: Johns Hopkins University Press. 

Weishampel DB, Barrett PM, Coria RA, Loeuff JL, Xing X, Xijin Z, Sahni A, Gomani EMP, and Noto CR. 2004. Dinosaur Distribution. In: Weishampel DB, Dodson P, and Osmólska H, eds: The Dinosauria, 2nd Edition. Berkeley: University of California Press. p. 517-617.

Self-Trail JM, Christopher RA, Prowell D, and Weems RE. 2004. The Age of Dinosaur-Bearing Strata at Phoebus Landing, Cape Fear River, North Carolina. Geological Society of America Abstracts with Programs 36(2):117.

Schwimmer DR, Sanders AE, Erickson BR, and Weems RE. 2015. A Late Cretaceous Dinosaur and Reptile Assemblage from South Carolina, USA. Transactions of the American Philosophical Society 105(2):1-157.

Longrich NR. 2016. A ceratopsian dinosaur from the Late Cretaceous of eastern North America, and implications for dinosaur biogeography. Cretaceous Research 57:199-207.

Kiernan K and Schwimmer DR. 2004. First record of a Velociraptorine theropod (Tetanurae, Dromaeosauridae) from the eastern Gulf Coastal United States. The Mosasaur 7:89-93.

 

Preprint Published: A Tyrannosauroid Metatarsus from the Merchantville Formation of Delaware increases the diversity of non-Tyrannosaurid Tyrannosauroids on Appalachia

Hello everyone. Recently, I have worked on describing several tyrannosaur specimens from the Cretaceous Formations of Atlantic Coastal Plain. One of the manuscripts I have written concerns a partial tyrannosaur metatarsus from the Merchantville Formation of Delaware. As of now, the preprint of this paper has been published, and you can find it here:

https://peerj.com/preprints/3097/

The metatarsus represents a distinct morphotype of tyrannosaur from Dryptosaurus or Appalachiosaurus, but nevertheless is too incomplete and lacking in distinguishing features to warrant the naming of a new specimen. Certainly, the diversity of tyrannosauroids on Appalachia has been underestimated.

 

PaleoNews #22: Appalachian ceratopsians and more!

Hello and welcome to this shorter edition of PaleoNews. This spring, a few finds related to the landmass of Appalachia have been published on, and so here’s a look back at those.

NEW FINDINGS

Though the find was published on by the media this past summer (e.g., here), the first-ever record of a ceratopsid dinosaur from Appalachia has been published on in the journal PeerJ. In the paper “The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA)” (Farke and Phillips, 2017), the discovery of a single tooth from the Maastrichtian Owl Creek Formation is discussed in the context of the biogeography of horned dinosaurs in North America during the Cretaceous. The paper also discusses the Maastrichtian-age deposit that is the Owl Creek Formation and its fauna in some detail, as well as giving a brief overview of the dinosaur clades which inhabited the landmass of Appalachia (Farke and Phillips, 2017).

In the paper, the authors conclude that a dispersal event of ceratopsid dinosaurs occurred in North America as the Western Interior Seaway retreated during the Maastrichtian, the last stage of the Cretaceous period (Farke and Phillips, 2017). Thus, the tooth is both significant for being the first report of a ceratopsid dinosaur from eastern North America as well as for suggesting a possible dispersal event during the Maastrichtian.

The MS find belonged to the ceratopsidae, as did Triceratops horridus (skull pictured above). 

I also had an article published on ornithomimosaur remains from the Arundel Clay of Maryland (Brownstein, 2017). The finds I describe are important for representing two distinct morphotypes (and thus possibly two distinct species) of ornithomimosaur that existed in the Arundel ecosystem. These dinosaurs would have coexisted with the titanosauriform sauropod Astrodon, the dromaeosaur Deinonychus, the carcharodontosaur Acrocanthosaurus, possibly the ornithopod Tenontosaurus, an indeterminate neoceratopsian, and the obscure nodosaurid Priconodon (e.g. Weishampel, 2006). There is certainly much more material to be published on from the Arundel Clay, so it should be exciting to see how the Arundel’s dinosaurs come to light.

Two of the pedal unguals representing one of the morphotypes of ornithomimosaur present in the Arundel. 

FEATURED FOSSIL 

Today, I feature the skull of the Aurochs (Bos primigenius), an extinct species of large bovine that inhabited the wilds of Europe, northern Africa, and Asia during the Pleistocene and into the Holocene. Julius Caesar, in book 6 of his Commentarii de Bello Gallico, writes on the fantastic size and power of these animals (Commentarii de Bello Gallico 6.28). I highly recommend you read his description, either in translation or the original latin, if you haven’t already, as it gives a seldom-attained glimpse of an extinct animal of a great awe-inspiring nature.

Overall, this has been a productive spring for Appalachian discoveries. Let’s hope for an even better summer! Thanks for reading.

References

Farke, A.A., and Phillips, G.E. 2017. The first reported ceratopsid dinosaur from eastern North America (Owl Creek Formation, Upper Cretaceous, Mississippi, USA. PeerJ, 5:e3342. 

Brownstein, C.D. 2017. Description of Arundel Clay ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an “Ostrich Dinosaur”: biogeographic implications. PeerJ, 5:e3110. 

Weishampel, D.B. 2006. Another look at the dinosaurs of the East Coast of North America, p. 129-168. In ‘Coletivo Arqueológico-Paleontológico Salense, (eds.), Actas III Jornadas Dinosaurios Entorno. Salas de los Infantes, Burgos, Spain.

 

Women in Paleontology: Mignon Talbot

Happy International Women’s Day everyone! Today, we are reminded of the struggles women have faced and still face around the globe as well as the countless contributions they have made and continue to make today to our world. I thus wanted to highlight one woman who contributed to paleontology in the eastern United States.

Mignon Talbot was born four years after the end of the Civil War in Iowa City, Iowa (Elder, 1982). Receiving her undergraduate education at Ohio State University, Talbot would go on to Yale to receive her doctorate in 1904 and would be appointed as an instructor of geology at Mt. Holyoke the same year (Elder, 1982). Dr. Talbot quickly ascended the ranks to become the chairman of the Geology department in 1908, and in 1929 would become chairman of both the Geology and Geography departments (Elder, 1982).

Over the course of her career, Dr. Talbot would greatly expand the Triassic ichnofossil and mineral collection at Mt. Holyoke, continuing to passionately do so even after a fire in 1916 would destroy most of the collection (Elder, 1982).

She would also publish a review of crinoids from the early Devonian (Helderbergian) strata of the state of New York (Talbot, 1905). This work would be part of her dissertation, for which she would have the trilobite researcher Dr. Charles Emerson Beecher as a supervisor (Talbot, 1905).

Perhaps her most notable discovery, however, was that of the coelophysoid dinosaur Podokesaurus holyokensis. Dr. Talbot would discover the partial skeleton of this dinosaur encased in cracked bolder near the college in 1910, becoming the first woman to name a non-avian dinosaur species the following year (Talbot, 1911; Turner, Burek & Moody, 2010). Dr. Talbot would remark on the chance of the find in the American Journal of Science in June of 1911 (Albino, accessed March 8, 2015). She would name Podokesaurus from the greek word for swift-footed, referencing the name of the university for which she worked in the specific epithet (Talbot, 1911).

Cast of the holotype of Podokesaurus on display at the Peabody Museum. Photo by the author, 2015.

Unfortunately, the skeleton of Dr. Talbot’s dinosaur would be destroyed in the 1916 fire that burned down Williston Hall (Albino, accessed March 8, 2015). Talbot would notably remark that she wished the specimen to go on exhibition at Yale or in Washington in the June 1911 issue of the American Journal of Science mentioned previously (Albino, accessed March 8, 2015). Nevertheless, Talbot was largely responsible for the growth of the Holyoke collection after the fire (Elder, 1982). She said to have been actively interested in the profession of paleontology to her death in 1950 (Elder, 1982).

Her contributions to paleontology in the eastern United States are invaluable. The specimen she discovered and described, though now destroyed, is one of the only skeletons of a dinosaur known from the east coast. She will forever remain the first woman to name one of the marvelous lizards.

For more on Podokesaurus, see this post.

References.

Elder E. 1982. Women in Early Geology. Journal of Geological Education 30(5): 287–293.

Talbot M. 1905. Revision of the New York Helderbergian crinoids. American Journal of Science (Series 4) 20(115): 17-34.

Talbot M. 1911. Podokesaurus holyokensis, a new dinosaur of the Connecticut Valley. American Journal of Science 31: 469-479

Turner S, Burek C & Moody RT. 2010. Forgotten women in an extinct Saurian ‘mans’ World. In Moody RT, Buffetaut E, Martill D, Naish D, eds: Dinosaurs and Other Extinct Saurians: A Historical Perspective. The Geological Society of London Special Publication 343: 111-153.

Albino D. Lost Dinosaur. URL:  http://www.mtholyoke.edu/~dalbino/books/lester/dinosaur.html. Accessed March 8, 2017.

 

 

PaleoNews #22: New Years 2016

Happy new year! It’s been an interesting year this time around, full of new discoveries pertaining to the landmass of Appalachia.

NEW FINDINGS THIS YEAR 

Perhaps the most covered story of a discovery from Appalachia was of the landmass’s newest hadrosaur. Eotrachodon orientalis, known from the likely juvenile holotype specimen MSC 7949, is the only named pre-Campanian non-lambeosaurine hadrosaurid and helps to fill in some of the gaps regarding the evolution of the hadrosaurid dinosaurs (Prieto-Márquez, Erickson & Ebersole, 2016a; 2016b). Eotrachodon is known from the Mooreville Chalk Formation, which has also preserved the remains of the hadrosauroid dinosaur Lophorhothon, the dromaeosaurid Saurornitholestes, and the alligatoroid crocodyliform Deinosuchus (e. g. Schwimmer, 2002; Kiernan & Schwimmer, 2004;Prieto-Márquez, Erickson & Ebersole, 2016a; 2016b). The holotype specimen of this dinosaur is surprisingly complete for an Appalachian dinosaur specimen, consisting of a mostly complete skull and partial skeleton (Prieto-Márquez, Erickson & Ebersole, 2016a; 2016b).

Eotrachodon is especially important because it represents an extremely close outgroup to the clade containing Lambeosaurinae and Saurolophinae (Prieto-Márquez, Erickson & Ebersole,2016a). Alongside the New Jersey taxon Hadrosaurus foulkii, Eotrachodon orientalis is one of the most basal hadrosaurids, suggesting that the group may have originated on Appalachia (Prieto-Márquez, Erickson & Ebersole, 2016a; 2016b).

Along with Hadrosaurus, Eotrachodon is one of the most basal hadrosaurids. Hadrosaurus foulkii fossils displayed at the Philadelphia Academy of Natural Sciences, Drexel University. Photo from Wikipedia.

Anné, Hedrick & Schein (2016) described the radius and ulna of a hadrosaurid dinosaur from the Navesink Formation of New Jersey. The elements in question were diagnosed with septic arthritis, the first known case of the ailment to be reported from the Dinosauria (Anné, Hedrick & Schein, 2016).

The forelimb elements provide new information on ailments which affected the dinosaurs, and are also significant for being an example of paleopathology from Appalachia (Anné, Hedrick & Schein, 2016).

Paulina-Carabajal, Lee & Jacobs (2016) examined the skull of the Texan nodosaur Pawpawsaurus campbelli. The endocast of Pawpawsaurus is one of the most well-known of a nodosaurid, thus allowing Paulina-Carabajal, Lee & Jacobs (2016) to examine the morphology of the dinosaur’s inner ear in detail.

 Scans of the internal structure of the skull and brain suggest that the nodosaurid had a poor sense of hearing (Paulina-Carabajal, Lee & Jacobs, 2016). However, Pawpawsaurus was also found to have a good sense of smell, albeit less so than more derived ankylosaurian genera (Paulina-Carabajal, Lee & Jacobs, 2016).

Pawpawsaurus campbelli walks along an Albian Texas shore alongside Protohadros-like hadrosauroids and a crocodyliform. 

Another nodosaurid from Appalachia was remarked on this year in the literature. Burns & Ebersole (2o16) published an abstract in the program & abstracts book of the 76th SVP annual meeting. The abstract dealt with some exciting new material of a juvenile nodosaurid from the same formation that produced Eotrachodon. The nodosaurid specimen is also one of the smallest known (Burns & Ebersole, 2016).

FEATURED FOSSIL 

This time around, we have the skull of the sebecid crocodyliform Sebecus. This large crocodyliform occupied a predatory niche in Argentina during the Eocene. 

All in all, it has been an exciting year of discoveries regarding the landmass of Appalachia. Here’s hoping for more in the new year. Happy holidays everyone!

 

References 

1. Prieto-Marquez A, Erickson GM, Ebersole JA. 2016. A primitive hadrosaurid from southeastern North America and the origin and early evolution of ‘duck-billed’ dinosaurs. J. Vert. Paleo. 2016; e1054495. doi: 10.1080/02724634.2015.1054495.

2. Prieto-Márquez A, Erickson GM, Ebersole JA. Anatomy and osteohistology of the basal hadrosaurid dinosaur Eotrachodon from the uppermost Santonian (Cretaceous) of southern Appalachia. PeerJ 2016; 4:e1872. doi: https://doi.org/10.7717/peerj.1872.

3. Schwimmer DR. King of the Crocodylians: The Paleobiology of Deinosuchus. Bloomington: Indiana University Press; 2002.

4. Kiernan K, Schwimmer DR. First record of a Velociraptorine theropod (Tetanurae, Dromaeosauridae) from the eastern Gulf Coastal United States. Mosasaur 2004; 7:89-93.

5. Anné J, Hedrick BP, Schein JP. 2016. First diagnosis of septic arthritis in a dinosaur. R. Soc. Op. Sci. 3: 160222. doi: 10.1098/rsos.160222.
6. Paulina-Carabajal A, Lee YN, Jacobs LL. 2016. Endocranial Morphology of the Primitive Nodosaurid Dinosaur Pawpawsaurus campbelli from the Early Cretaceous of North America. PLoS ONE 11(3): e0150845. doi:10.1371/journal.pone.0150845.
7. Burns ME, Ebersole J. 2016. Juvenile Appalachian Nodosaur Material (Nodosauridae, Ankylosauria) from the Lower Campanian Lower Mooreville Chalk of Alabama. J. Vert. Paleo. 2016; 76: 73B.

Thanksgiving My Oh My!

EDIT: I’ve added a link to my preprint on the Maryland theropod remains published this past summer. I’ve focused in a little more on some stuff now but I think it gives a good overview of what I’m focused on.

What a weekend this has been! I’ve finally been able to submit a big biogeography paper I’ve been working on for a while (started writing it last spring) and I have also managed to resubmit another revised manuscript. Sorry I haven’t been posting anything recently, but this year has been rather hectic in terms of research and traveling. Here’s a quick peak into what I’ve been up to.

Some highlights since I last blogged:

In August, I traveled to Dinosaur Ridge, located just outside the Colorado capital of Denver, to view the awe-inspiring trackways which line the sides of an old road which is now used as a bike trail. The large ornithopod tracks (which were mentioned to possibly made by the hadrosauroid Eolambia) and ornithomimosaur tracks were quite stunning. To my pleasant surprise, they also had a site from the Morrison Formation which held oh-so-pretty mahogany colored bones. The views of the red Morrison Formation rocks were absolutely stunning. Those rocks are of the same layer as those which cradle the famous Red Rocks Amphitheater.

The small museum at the Dinosaur Ridge main building was also a nice addition to the day. The people at Dinosaur Ridge have done a very good job of telling a story about the site in the context of the changing geography of North America during the Jurassic and Cretaceous. I especially admired their use of paleogeographic maps with displays on each period of time represented at Dinosaur Ridge in order to really give a greater perspective on the fossils. The displays also excelled at what I find some museums often do not. They gave not only a picture of the dinosaurs and other “cool” animals which lived at Dinosaur Ridge during each period in time, but also gave a picture of the entire environment. The murals by Michael Skrepnick were also lovely, and a life-size outdated Utahraptor sculpture was an amusing addition to the portion of the museum within the building.

Outside, a well-made life-sized Eolambia sculpture shadowed another little display of some Allosaurus bones. All in all, the museum was very good and I definitely recommend checking it out along with viewing the famous trackway.

Here are a few pictures of the museum, the main trackway on the ridge, and the views from Dinosaur Ridge.

A friendly brachiosaur greets incoming visitors, while a rather murderous-looking Utahraptor peeks at new arrivals to the museum. Check out those cervicals. Eat your heart out, SV-POW!

 

The main track site.

A closer view of the purported Eolambia tracks. The smaller tracks indicate a juvenile ornithopod walking alongside an adult.

View from the ridge.

On September 18th, I had the honor of presenting some of my research on the paleobiogeography and paleoecology of Appalachian dinosaurs at a meeting for the New York Paleontological Society (NYPS). I heard a number of great talks during the meeting, including one on trilobites from the northeast and another on the formation of arches in rock.

The talk centered around research I’ve been doing for the paper I mentioned above which is centered on comparing dinosaur faunas from Appalachia with other faunas across the globe.

In October, I ventured to the AMNH to view some interesting theropod material from the Cretaceous of New Jersey. I don’t want to give too much away, but I hope to start writing a paper on the specimens I viewed pretty soon. Thank you to Carl Mehling for hosting me!

The weekend before thanksgiving, I was able to travel to Maryland to view some theropod material within the Dinosaur Park collections. The farmland and countryside around the Dinosaur Park site was very pretty. I’ve added a picture below of some of the farmland, which was a very nice treat before a long day of driving. Thanks to Ben at Extinct Monsters for hosting me and showing me the collections. The preprint from this past summer can be found here.

 

I hope I’ll have some more time to blog soon, and thanks for bearing with me until now. I have a couple of ideas for what species I will feature for the next Antediluvian Beasts, so I’ll hopefully be able to write up an article. Happy Thanksgiving and thanks for reading!

 

 

 

Antediluvian Beasts of the East: Daeodon leidyanus

Draining from the early Miocene Appalachian mountains are the streams and creeks which flow through the woodlands of New Jersey until they reach the blue Atlantic. Fed by mountain lakes and aquifers, these meandering waterways provide a much-needed source of liquid to the parched lowlands of the summer. Flowers and grasses shoot up through the cracked ground as the fluid product of the rainy season in the mountains turns the earth the deep brown and the tree leaves a healthier color. Though the temperature still peaks at over 32° Celsius (90° Fahrenheit), many large herbivores can be found in these coastal forests. Gigantic two-horned semiaquatic rhinoceros settle down into the waterholes of clearings. Three-toed horses race through the woods and munch on tree leaves as peccaries squabble over roots and burrow sites. Extinct distant relatives of modern mouse deer with two horns at the back of their skulls and a branching one at the front of their snouts compete for mates and territory, wearily checking the surrounding trees every few minutes for signs of danger. In the seas, multiple species of gargantuan sharks vie for chow with ancient relatives of sperm whales with gargantuan teeth an jaws as  other species of whales bask and play near the surface, their calls heard for miles. Mollusks scavenge on the sea floor as fish schools swim along.

Back on land, a group of peccaries jog through their favorite mud hole through an open patch of grass and flowers. The size of modern javelinas, these herbivorous mammals are often left to their devices by predators and other herbivores weary of sustaining an injury from the peccaries’ large front tusks. Even the rhinoceros, the largest animals to roam these forests, are weary of the smaller mammals. 

As the peccaries cross the opening in the forest unaware, a huge predator stalks them. The gleaming eyes of this colossus give off the faintest light on the predator’s distorted muzzle. Covered with scars, cuts and the occasional protuberance, it would appear that this creature is of another nature from the other mammals of early Miocene New Jersey. However, it is nonetheless the largest mammalian predator to stalk this forest. This is an entelodont, a relative of the group of mammals which includes hippopotami and whales. However, the grizzly, misleadingly hog-like appearance and terrifying predatory behavior of this odd mammal has given it the more ominous name of “terminator pig”. The massive front teeth of this humongous beast are rooted into its robust, meter-long skull. Its large body, built with powerful shoulder muscles and powerful, hoofed limbs to overpower its quarries, slopes down into a small tail tipped with fur. 

From the bushes, the terminator pig charges at the peccary group, which scatter in fear. However, the large carnivore has outplayed the smaller tusked mammals, and has snagged the belly of one peccary on its canines. As blood loss takes its toll, the panicked ensnared peccary tries at its large attacker with its front teeth, scraping the terminator pig’s chin. The counterattacks are of no help to the peccary, who soon dies in the jaws of the larger mammal. With a single bite, the entelodont devours a large portion of the peccary’s gut, though it will stash away the rest of its kill in a hole created by the roots of a fallen tree which the carnivore inhabits. 

Though the Miocene exposures of the east coast of the United States are more famous for their marine fossils, like those of the gigantic shark C. megalodon and the toothed whale Squalodon, a variety of equally incredible animals roamed the land. Unfortunately, these incredible animals, some of which among the largest predators North America would ever see, have not gotten the attention which they deserve.

One such carnivore, a mammal known as an entelodont, left its fossil mark in Farmingdale, New Jersey in the form of a left premolar and molar named Ammodon leidyanum by the famous paleontologist Othneil Charles Marsh (Marsh, 1893). Though another famous paleontologist, Edward Drinker Cope, speculated that the teeth came from a pig-like creature, more finds in the northwest United States would be needed to reveal the animal’s true identity (Gallagher, 1997).

In the end, the mystery of Marsh’s Ammodon leidyanum was solved. The mammal, now known to be an entelodont, was a large, gruesome predator with large teeth and the occasional bony protuberance off of its lower jaw to create a distinctive-looking skull. These big slashing teeth would have been able to rip into the flesh of the large mammals of early Miocene New Jersey, feeding the meat to the entelodont’s premolars and molars, which would start to grind and crush whatever the predator decided to swallow. Their long muzzles would have connected to a large, robust body supported by relatively thin, hoofed limbs. Among the classic features of the entelodonts were two bony lumps which extended from the skull.

More recent additions to the scientific literature had discussed whether Ammodon was truly a valid genus name for the Farmingdale entelodont teeth. In 1998, a remarkable conclusion as to the identity of the teeth was reached. It would seem that the teeth actually belong to a species of the western North American entelodont genus Daeodon, the largest known genus of entelodont (Lucas, Emry & Foss, 1998). Large individuals of this genus could have the shoulder height the height of a man. The holotype tooth of the Farmingdale creature is slightly larger and longer than the same element in western Daeodon (Lucas, Emry & Foss, 1998), which may suggest that the New Jersey animal was either larger than its relative from the American West or had larger teeth.

The approximately one meter long skull of a western Daeodon at the Denver Museum of Nature and Science. Note the large front teeth. Photo by the author, 2014. 

The entelodonts as a group had evolved to pursue and attack the large mammals which benefited off of the plants of the plains and forests of North America, though they would occasionally chow on tubers and roots to supplement their primarily carnivorous diet. Like modern large mammalian predators, entelodonts were opportunistic, scavenging carcasses on occasion. In New Jersey, Daeodon leidyanum would have been a part of the Farmingdale local fauna of the basal Kirkwood Formation of coastal New Jersey (Tedford & Hunter, 1984; Gallagher et. al., 1995). This assemblage of mammals has yielded the remains of the three-toed horse Anchitherium, the rhinoceroses Diceratherium matutinum and Menoceras, the protoceratid Prosynthetoceras, and the peccary Hesperohyus antiquus (Tedford & Hunter, 1984; Gallagher, 1997), and is likely Arikareean in age (Lucas, Emry & Foss, 1998).

Daeodon full body model at the Denver Museum of Nature and Science. Photo by the author, 2014. 

The relations of the entelodonts have been reflected on by many researchers, and in among the most recent additions to the literature, and the researchers involved found that the pig-like appearance of the entelodonts from which they get their popular nicknames (i.e., “terminator pig”) is rather misleading. Rather, the entelodonts seem to be more closely related to whales and hippopotami in a group termed the cetancodontamorpha (Spaulding, O’Leary & Gatesy, 2009).

In life, Daeodon leidyanum would have been a truly horrific sight as it hunted down fleeing mammals in the coastal forests of New Jersey. This ancient king of the forest was part of a great dynasty of carnivorous beasts which would only fall to extinction after many millions of years of success. Daeodon shows how wrong the belief is that extinction must mean some sort of evolutionary failure. Rather, the entelodonts were a success story, though like all species were unfit for some changing condition or conditions in their ecosystem, leaving only their devilish skulls and ancient skeletons behind for future creatures to observe.

Daeodon leidyanus by the author. Pencils on paper, 2016. 

For more on large mammalian predators of the eastern United States, see:

Antediluvian Beasts of the East: Pliocyon robustus

References.

Marsh OC. 1893. Description of Miocene Mammalia. American Journal of Science 46(275): 407-412.

Gallagher WB. 1997. When Dinosaurs Roamed New Jersey. New Brunswick: Rutgers University Press. pp. 142.

Lucas SG, Emry RJ & Foss SE. 1998.Taxonomy and distribution of Daeodon, an Oligocene-Miocene entelodont (Mammalia: Artiodactyla) from North America. Proceedings of the Biological Society of Washington 111(2): 425-435.

Tedford RH & Hunter ME. 1984. Miocene marine-nonmarine correlations, Atlantic and Gulf Coastal Plains, North America. Paleogeography, Paleoclimatology, Paleoecology 47: 129-151.

Gallagher WB, Gilmore EJ, Parris DC, Grandstaff BS. 1995. Miocene mammals from the Kirkwood Formation of Monmouth County, N. J. In Baker JEB, ed: Contributions to the paleontology of New Jersey. Geological Association of New Jersey 12: 254-268.

Spaulding M, O’Leary MA & Gatesy J. 2009. Farke, AA ed. Relationships of Cetacea (Artiodactyla) Among Mammals: Increased Taxon Sampling Alters Interpretations of Key Fossils and Character Evolution. PLoS ONE 4(9): e7062.