Summary of quantitative morphotypes showing their stratigraphic ages. (Credit: Derek W. Larson, Philip J. Currie. Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time. PLoS ONE, 2013; 8 (1): e54329 DOI: 10.1371/journal.pone.0054329)

More Small Meat-Eating Dinosaurs Than Thought

Jan. 23, 2013 — University of Alberta researchers used fossilized teeth to identify at least 23 species of small meat-eating dinosaurs that roamed western Canada and the United States, 85 to 65 million years ago.

Until now, only seven species of small two-legged meat-eating dinosaurs from the North American west had been identified.

U of A palaeontologist Philip Currie and student Derek Larson examined a massive dataset of fossil teeth that included samples from members of the families to which Velociraptor and Troodon (possibly the brainiest dinosaur) belong.

"Small meat-eating dinosaur skeletons are exceedingly rare in many parts of the world and, if not for their teeth, would be almost completely unknown," said Larson.

The researchers say the huge increase in the number of small meat-eating species to 23, shows that instead of a few species existing for many millions of years, there were actually many small meat-eating species, each existing for shorter periods of time.

"We can identify what meat-eaters lived in what geographic area or geologic age," explained Currie. "And we can do this by identifying just their teeth, which are far more common than skeletons."

Story Source:

The above story is reprinted from materials provided by University of Alberta, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Derek W. Larson, Philip J. Currie. Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time. PLoS ONE, 2013; 8 (1): e54329 DOI: 10.1371/journal.pone.0054329

University of Alberta (2013, January 23). More small meat-eating dinosaurs than thought. ScienceDaily. Retrieved January 24, 2013, from http://www.sciencedaily.com /releases/2013/01/130123195356.htm

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Photographs of the braincase of the titanosaurian sauropod Ampelosaurus sp. (MCCM-HUE-8741) from the Cretaceous of Fuentes, Spain. In dorsal (A), ventral (B), rostral (C), caudal (D), and left lateral (E) views. Abbreviations: BO, basioccipital; BS, basisphenoid; EO-OP, exoccipital-opisthotic/otoccipital; F, frontal; LS, laterosphenoid; OS, orbitosphenoid; P, parietal; PR, prootic; SO, supraoccipital. Scale bar equals 5 cm. (Credit: Knoll et al. Neurocranial Osteology and Neuroanatomy of a Late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.). PLoS ONE, 2013; DOI: 10.1371/journal.pone.005499

Brain of Ampelosaur from Cuenca (Spain) Revealed

Jan. 23, 2013 — Scientists have made a 3D reconstruction of the remains of ampelosaur, found in 2007 in the site of Lo Hueco (Cuenca). The fossils are about 70 million years old (Late Cretaceous).

Up to now, only one species of the genus was known, Ampelosaurus atacis, which was discovered in France. The differences between the Spanish and the French fossils do not rule out that they could represent distinct species.

The researcher from the National Museum of Natural Sciences (CSIC) Fabien Knoll, who has conducted the investigation, considers that "more fossils are necessary to establish that we are dealing with a new species." For this reason, the team has identified the specimen as Ampelosaurus sp., which leaves open its specific identity.

Little evolved brain

The ampelosaur pertains to the sauropod group, large-sized dinosaurs that settled widely during the Mesozoic Era (which began 253 million years ago and ended 66 million years ago). More precisely, it is a titanosaur, a group of plant eating animals that were dominant during the last half of the Cretaceous (last period of the Mesozoic). The first sauropods appeared about 160 million years earlier than the ampelosaur.

However, despite being the product of a long evolution, the brain of the ampelosaur does not show any notable development. Knoll explains: "This saurian may have reached 15 m in length; nonetheless its brain was not in excess of 8 cm." According to the CSIC researcher: "Increase in brain size was not favored in the course of sauropod evolution."

Another of the characteristics yielded by the reconstruction of the Cuenca ampelosaur brain is the small size of the inner ear. According to Knoll: "This may suggest that the ampelosaur would not have been adapted to quickly move either its eyes or its head and neck."

In January of 2012, Knoll conducted the investigation that led to the reconstruction of another sauropod, Spinophorosaurus nigeriensis. The simulation in 3D of its brain revealed that that species, in contrast to what the study of the ampelosaur braincase demonstrated, presented a fairly well-developed inner ear.

According to the one of the researchers, "It is quite enigmatic that sauropods show such a diverse inner ear morphology whereas they have a very homogenous body shape; more investigation is definitely required."

Story Source:

The above story is reprinted from materials provided by Spanish National Research Council (CSIC), via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Fabien Knoll, Ryan C. Ridgely, Francisco Ortega, Jose Luis Sanz, Lawrence M. Witmer. Neurocranial Osteology and Neuroanatomy of a Late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.). PLoS ONE, 2013; 8 (1): e54991 DOI: 10.1371/journal.pone.0054991

Spanish National Research Council (CSIC) (2013, January 23). Brain of ampelosaur from Cuenca (Spain) revealed. ScienceDaily. Retrieved January 24, 2013, from http://www.sciencedaily.com /releases/2013/01/130123195349.htm

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This is a Malapa fox fossil. (Credit: Wits University)

Previous Unknown Fossilized Fox Species Found

Jan. 23, 2013 — Researchers from Wits University, the University of Johannesburg and international scientists announced on January 22, 2012, the discovery of a two million year old fossil fox at the now renowned archaeological site of Malapa, South Africa, in the Cradle of Humankind World Heritage Site.

In an article published in the journal Transactions of the Royal Society of South Africa, the researchers describe the previously unknown species of fox named Vulpes Skinneri -- named in honour of the recently deceased world renowned South African mammalogist and ecologist, Prof. John Skinner of the University of Pretoria.

The site of Malapa has, since its discovery in 2008, yielded one of the most extraordinary fossil assemblages in the African record, including skeletons of a new species of human ancestor named Australopithecus sediba, first described in 2010.

The new fox fossils consist of a mandible and parts of the skeleton and can be distinguished from any living or extinct form of fox known to science based on proportions of its teeth and other aspects of its anatomy.

Dr. Brian Kuhn of Wits' Institute for Human Evolution (IHE) and the School of GeoSciences, an author on the paper and head of the Malapa carnivore studies explains: "It's exciting to see a new fossil fox. The ancestry of foxes is perhaps the most poorly known among African carnivores and to see a potential ancestral form of living foxes is wonderful."

Prof. Lee Berger, also of the IHE and School of GeoSciences, author on the paper and Director of the Malapa project notes: "Malapa continues to reveal this extraordinary record of past life and as important as the human ancestors are from the site, the site's contribution to our understanding of the evolution of modern African mammals through wonderful specimens like this fox is of equal import. Who knows what we will find next?."

The entire team has expressed their privilege in naming the new species after "John Skinner, one of the great names in the study of African mammals and particularly carnivores. We (the authors) think that John would be pleased, and it is fitting that this rare little find would carry his name forever."

Story Source:

The above story is reprinted from materials provided by University of the Witwatersrand.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Adam Hartstone-Rose, Brian F. Kuhn, Shahed Nalla, Lars Werdelin, Lee R. Berger. A new species of fox from the Australopithecus sediba type locality, Malapa, South Africa. Transactions of the Royal Society of South Africa, 2013; : 1 DOI: 10.1080/0035919X.2012.748698

University of the Witwatersrand (2013, January 23). Previous unknown fossilized fox species found. ScienceDaily. Retrieved January 24, 2013, from http://www.sciencedaily.com /releases/2013/01/130123115350.htm