Basanti Husain and his colleagues made an important discovery.

“We think that they might see a clear correlation,” says Husain.

What makes it special is that the group found evidence from both the Cretaceous and Miocene eras for the same geological feature. And there have been a number of previous analyses using computer models that suggest the feature’s presence in those periods.

“We do not think that these fossils imply that the Cretaceous was just a blank slate,” says Chris Stringer of the Museum of the Rockies in Colorado, who was not involved with the work.

“We think that it’s telling us about when this feature was first present,” says Husain.

The paper comes almost exactly 65 years after the initial discovery. It is not clear whether the researchers will find similar fossils or even dinosaur bones from the same part of Colorado.

The results will appear in the Journal of Vertebrate Paleontology.

“In the last few years, there has been a lot of research showing that the entire Upper Cretaceous is really a blank slate,” says Stringer.

“A lot of the dinosaur families are starting to come back,” and there is evidence that these early fossils and those of species such as Triceratops, Apatosaurus and Stegosaurus were living in different regions at different times.

The fossils are a reminder of the diversity present at that time, says Stringer.

“These are the few examples that tell you what kind of animals were out there,” says Stringer.

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Reference: “Evolutionary relationships among Late Cretaceous and early Miocene vertebrate fossils in the northeastern US,” by Basanti A. Husain et al. Journal of Vertebrate Paleontology, published online April 16, 2013

More information:

The paper is available online here: http://www.pnas.org/content/early/2013/04/17/1301193712

Comments

Pam de la Peña

University of California, Berkeley, Berkeley, CA 94720

Cell: 510-826-1320

E-mail: de.pamdepeñ[email protected]

The Nature paper: http://www.nature.com/ncomms/2013/1305789-mars-neb