Tag Archives: Dinosaurs

A what..?!? Semiaquatic basal dromaeosaur

Hi all,

Ah, life is wonderful. 🙂

https://www.nature.com/articles/nature24679

Cau, A., Beyrand, V., Voeten, D. F. A. E., Fernandez, V., Tafforeau, P., Stein, K., Barsbold, R., Tsogtbaatar, K., Currie, P. J. & Godefroit, P., 2017: Synchrotron scanning reveals amphibious ecomorphology in a new clade of bird-like dinosaurs.
–Nature: in press [doi: 10.1038/nature24679]

Abstract:

“Maniraptora includes birds and their closest relatives among theropod dinosaurs. During the Cretaceous period, several maniraptoran lineages diverged from the ancestral coelurosaurian bauplan and evolved novel ecomorphologies, including active flight, gigantism, cursoriality and herbivory. Propagation X-ray phase-contrast synchrotron microtomography of a well-preserved maniraptoran from Mongolia, still partially embedded in the rock matrix, revealed a mosaic of features, most of them absent among non-avian maniraptorans but shared by reptilian and avian groups with aquatic or semiaquatic ecologies. This new theropod, Halszkaraptor escuilliei gen. et sp. nov., is related to other enigmatic Late Cretaceous maniraptorans from Mongolia in a novel clade at the root of Dromaeosauridae. This lineage adds an amphibious ecomorphology to those evolved by maniraptorans: it acquired a predatory mode that relied mainly on neck hyperelongation for food procurement, it coupled the obligatory bipedalism of theropods with forelimb proportions that may support a swimming function, and it developed postural adaptations convergent with short-tailed birds.”

Cheers!!

–Mikko H.

Dino-tail in Amber!

‘Beautiful’ dinosaur tail found preserved in amber

http://www.bbc.com/news/science-environment-38224564

Xing, L., McKellar, R. C., Xu, X., Li, G., Bai, M., Persons, W. S. I. V., Miyashita, T., Benton, M. J., Zhang, J., Wolfe, A. P., Yi, Q., Tseng, K., Ran, H. & Currie, P. J., A Feathered Dinosaur Tail with Primitive Plumage Trapped in Mid-Cretaceous Amber.

–Current Biology: in press [doi: 10.1016/j.cub.2016.10.008]

 

Encounter of the Giants of Berlin

More top quality science from the MfN.

Dinosaurs on Youtube

When we prepared the Spinosaurus exhibition, we realized that both Spinosaurus and T. rex have each a very large and also very emotional fanbase discussing lively whether the two could have met and how a fight would have ended. We have published a video starring Heinrich Mallison, Daniela Schwarz and Nizar Ibrahim looking at the facts and fiction of such online videos and discussions. Enjoy watching it here:https://youtu.be/Rz6vF0MyCnQ. We’d be happy if you like to share the video on your social networks (Twitter: @mfnberlin, Facebook@ Museum für Naturkunde Berlin).

 

Comments on Jurassic World in IltaSanomat by Maija & Mikko (in Finnish)

All,

Maija Karala and I gave a little interview and opinions to IltaSanomat of the Jurassic World.

Unfortunately it’s is only in Finnish.

http://www.istv.fi/viihde/vid-1435047061124.html

Those who haven’t yet watched the trailers, do so, it helps to understand some comments.

http://www.jurassicworldmovie.com/#

http://www.jurassicworld.com

–Mikko H.

More:
http://www.iltasanomat.fi/elokuvat/art-1435194630387.html

-Allu

Sexual dimorphism in Stegosaurus!

Saitta ET (2015) Evidence for Sexual Dimorphism in the Plated Dinosaur Stegosaurus mjosi (Ornithischia, Stegosauria) from the Morrison Formation (Upper Jurassic) of Western USA. PLoS ONE 10(4): e0123503. doi:10.1371/journal.pone.0123503

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0123503

Conclusive evidence for sexual dimorphism in non-avian dinosaurs has been elusive. Here it is shown that dimorphism in the shape of the dermal plates of Stegosaurus mjosi (Upper Jurassic, western USA) does not result from non-sex-related individual, interspecific, or ontogenetic variation and is most likely a sexually dimorphic feature. One morph possessed wide, oval plates 45% larger in surface area than the tall, narrow plates of the other morph. Intermediate morphologies are lacking as principal component analysis supports marked size- and shape-based dimorphism. In contrast, many non-sex-related individual variations are expected to show intermediate morphologies. Taphonomy of a new quarry in Montana (JRDI 5ES Quarry) shows that at least five individuals were buried in a single horizon and were not brought together by water or scavenger transportation. This new site demonstrates co-existence, and possibly suggests sociality, between two morphs that only show dimorphism in their plates. Without evidence for niche partitioning, it is unlikely that the two morphs represent different species. Histology of the new specimens in combination with studies on previous specimens indicates that both morphs occur in fully-grown individuals. Therefore, the dimorphism is not a result of ontogenetic change. Furthermore, the two morphs of plates do not simply come from different positions on the back of a single individual. Plates from all positions on the body can be classified as one of the two morphs, and previously discovered, isolated specimens possess only one morph of plates. Based on the seemingly display-oriented morphology of plates, female mate choice was likely the driving evolutionary mechanism rather than male-male competition. Dinosaur ornamentation possibly served similar functions to the ornamentation of modern species. Comparisons to ornamentation involved in sexual selection of extant species, such as the horns of bovids, may be appropriate in predicting the function of some dinosaur ornamentation.

But wait, there’s more!

Jacqueline

Brontosaurus is back!

“In this case, a number of specimens all previously identified as Brontosaurus in the past do actually come out together as close relatives of one another, and, although still close to Apatosaurus, are separate from this genus and show several distinct features that suggest they are different. Since the name Brontosaurus already exists for these animals, a new name doesn’t need to be created and instead the ‘thunder lizard’ (surely this wonderfully evocative translation is a large part of its popularity) is resurrected for them and thus returns to the ranks of the dinosaurs.”

http://www.theguardian.com/science/lost-worlds/2015/apr/07/the-thunder-lizard-returns-brontosaurus-resurrected

Actual scientific paper (which does mention the resurrection of Brontosaurus in the abstract but focuses on other aspects of Diplodocidae systematics and taxonomy):

https://peerj.com/articles/857/

And a little bit more from the authors:

https://peerj.com/blog/post/111369042783/emanuel-tschopp-diplodocidae/

Recent interesting paleonews

Welker, F., Collins, M. J., Thomas, J. A., Wadsley, M., Brace, S., Cappellini, E., Turvey, S. T., Reguero, M., Gelfo, J. N., Kramarz, A., Burger, J., Thomas-Oates, J., Ashford, D. A., Ashton, P. D., Rowsell, K., Porter, D. M., Kessler, B., Fischer, R., Baessmann, C., Kaspar, S., Olsen, J. V., Kiley, P., Elliott, J. A., Kelstrup, C. D., Mullin, V., Hofreiter, M., Willerslev, E., Hublin, J.-J., Orlando, L., Barnes, I. & MacPhee, R. D. E., 2015: Ancient proteins resolve the evolutionary history of Darwin/’s South American ungulates.
–Nature: in press [doi: 10.1038/nature14249]
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14249.html

Abstract:
No large group of recently extinct placental mammals remains as evolutionarily cryptic as the approximately 280 genera grouped as ‘South American native ungulates’. To Charles Darwin, who first collected their remains, they included perhaps the ‘strangest animal[s] ever discovered’. Today, much like 180 years ago, it is no clearer whether they had one origin or several, arose before or after the Cretaceous/Palaeogene transition 66.2 million years ago, or are more likely to belong with the elephants and sirenians of superorder Afrotheria than with the euungulates (cattle, horses, and allies) of superorder Laurasiatheria. Morphology-based analyses have proved unconvincing because convergences are pervasive among unrelated ungulate-like placentals. Approaches using ancient DNA have also been unsuccessful, probably because of rapid DNA degradation in semitropical and temperate deposits. Here we apply proteomic analysis to screen bone samples of the Late Quaternary South American native ungulate taxa Toxodon (Notoungulata) and Macrauchenia (Litopterna) for phylogenetically informative protein sequences. For each ungulate, we obtain approximately 90% direct sequence coverage of type I collagen α1- and α2-chains, representing approximately 900 of 1,140 amino-acid residues for each subunit. A phylogeny is estimated from an alignment of these fossil sequences with collagen (I) gene transcripts from available mammalian genomes or mass spectrometrically derived sequence data obtained for this study. The resulting consensus tree agrees well with recent higher-level mammalian phylogenies. Toxodon and Macrauchenia form a monophyletic group whose sister taxon is not Afrotheria or any of its constituent clades as recently claimed, but instead crown Perissodactyla (horses, tapirs, and rhinoceroses). These results are consistent with the origin of at least some South American native ungulates from ‘condylarths’, a paraphyletic assembly of archaic placentals. With ongoing improvements in instrumentation and analytical procedures, proteomics may produce a revolution in systematics such as that achieved by genomics, but with the possibility of reaching much further back in time.

Zanno, L. E., Drymala, S., Nesbitt, S. J. & Schneider, V. P., 2015: Early crocodylomorph increases top tier predator diversity during rise of dinosaurs.
–Scientific Reports: Vol. 5, art.no. 9276 [doi: 10.1038/srep09276]
http://www.nature.com/srep/2015/150319/srep09276/full/srep09276.html

Abstract:
Triassic predatory guild evolution reflects a period of ecological flux spurred by the catastrophic end-Permian mass extinction and terminating with the global ecological dominance of dinosaurs in the early Jurassic. In responding to this dynamic ecospace, terrestrial predator diversity attained new levels, prompting unique trophic webs with a seeming overabundance of carnivorous taxa and the evolution of entirely new predatory clades. Key among these was Crocodylomorpha, the largest living reptiles and only one of two archosaurian lineages that survive to the present day. In contrast to their existing role as top, semi-aquatic predators, the earliest crocodylomorphs were generally small-bodied, terrestrial faunivores, occupying subsidiary (meso) predator roles. Here we describe Carnufex carolinensis a new, unexpectedly large-bodied taxon with a slender and ornamented skull from the Carnian Pekin Formation (~231 Ma), representing one of the oldest and earliest diverging crocodylomorphs described to date. Carnufex bridges a problematic gap in the early evolution of pseudosuchians by spanning key transitions in bauplan evolution and body mass near the origin of Crocodylomorpha. With a skull length of >50 cm, the new taxon documents a rare instance of crocodylomorphs ascending to top-tier predator guilds in the equatorial regions of Pangea prior to the dominance of dinosaurs.

Van Roy, P., Daley, A. C. & Briggs, D. E. G., 2015: Anomalocaridid trunk limb homology revealed by a giant filter-feeder with paired flaps.
–Nature: in press [doi: 10.1038/nature14256]
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14256.html

Abstract:
Exceptionally preserved fossils from the Palaeozoic era provide crucial insights into arthropod evolution, with recent discoveries bringing phylogeny and character homology into sharp focus. Integral to such studies are anomalocaridids, a clade of stem arthropods whose remarkable morphology illuminates early arthropod relationships and Cambrian ecology. Although recent work has focused on the anomalocaridid head, the nature of their trunk has been debated widely. Here we describe new anomalocaridid specimens from the Early Ordovician Fezouata Biota of Morocco19, which not only show well-preserved head appendages providing key ecological data, but also elucidate the nature of anomalocaridid trunk flaps, resolving their homology with arthropod trunk limbs. The new material shows that each trunk segment bears a separate dorsal and ventral pair of flaps, with a series of setal blades attached at the base of the dorsal flaps. Comparisons with other stem lineage arthropods indicate that anomalocaridid ventral flaps are homologous with lobopodous walking limbs and the endopod of the euarthropod biramous limb, whereas the dorsal flaps and associated setal blades are homologous with the flaps of gilled lobopodians (for example, Kerygmachela kierkegaardi, Pambdelurion whittingtoni) and exites of the ‘Cambrian biramous limb’. This evidence shows that anomalocaridids represent a stage before the fusion of exite and endopod into the ‘Cambrian biramous limb’, confirming their basal placement in the euarthropod stem, rather than in the arthropod crown or with cycloneuralian worms. Unlike other anomalocaridids, the Fezouata taxon combines head appendages convergently adapted for filter-feeding with an unprecedented body length exceeding 2 m, indicating a new direction in the feeding ecology of the clade. The evolution of giant filter-feeding anomalocaridids may reflect the establishment of highly developed planktic ecosystems during the Great Ordovician Biodiversification Event.

Aquilops americanus

A Ceratopsian Dinosaur from the Lower Cretaceous of Western North America, and the Biogeography of Neoceratopsia
Farke AA, Maxwell WD, Cifelli RL, Wedel MJ
PLoS ONE 9(12): e112055
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0112055

And here’s a bit more about the ‘the tiny plant eater, Aquilops americanus, that suggests horned dinosaurs originated in Asia’.

http://www.theguardian.com/science/2014/dec/10/skull-oldest-horned-dinosaur-north-america-found


– Jacqueline  & Laura

Chicken from Hell!

Scientists have discovered a freakish, birdlike species of dinosaur — 11 feet long, 500 pounds, with a beak, no teeth, a bony crest atop its head, murderous claws, prize-fighter arms, spindly legs, a thin tail and feathers sprouting all over the place. Officially, it’s a member of a group of dinosaurs called oviraptorosaurs.

Unofficially, it’s the Chicken From Hell.

http://www.washingtonpost.com/national/health-science/new-dinosaur-called-the-chicken-from-hell/2014/03/19/92cc64d4-af7d-11e3-9627-c65021d6d572_story.html

A New Large-Bodied Oviraptorosaurian Theropod Dinosaur from the Latest Cretaceous of Western North America

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0092022;jsessionid=C7AB21F731D3D109E75C477194447051

__________________________________

Laura