Wednesday, May 20, 2009

Darwinius masillae: New Messel Primate

Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology. 2009. J. Franzen, et al. PloS One 4(5): e5723.

Abstract [edit]: The best European locality for complete Eocene mammal skeletons is Grube Messel, near Darmstadt, Germany. Although the site was surrounded by a para-tropical rain forest in the Eocene, primates are remarkably rare there, and only eight fragmentary specimens were known until now. Messel has now yielded a full primate skeleton. The specimen has an unusual history: it was privately collected and sold in two parts, with only the lesser part previously known. The second part, which has just come to light, shows the skeleton to be the most complete primate known in the fossil record.

The specimen is described as Darwinius masillae n.gen. n.sp. belonging to the Cercamoniinae. Skull radiography shows a host of teeth developing within the juvenile face. Investigation of growth and proportion suggest that the individual was a weaned and independent-feeding female that died in her first year of life, and might have attained a body weight of 650–900 g had she lived to adulthood. She was an agile, nail-bearing, generalized arboreal quadruped living above the floor of the Messel rain forest.

Micro-CT of the skull of Darwinius masillae
Darwinius masillae represents the most complete fossil primate ever found, including both skeleton, soft body outline and contents of the digestive tract. Study of all these features allows a fairly complete reconstruction of life history, locomotion, and diet.

Any future study of Eocene-Oligocene primates should benefit from information preserved in the Darwinius holotype. Of particular importance to phylogenetic studies, the absence of a toilet claw and a toothcomb demonstrates that Darwinius masillae is not simply a fossil lemur, but part of a larger group of primates, Adapoidea, representative of the early haplorhine diversification.

Vist the promo page for info on the upcoming book and documentary.

Thanks to Lisa for the head's up on this.

While the blog was dormant for the past few weeks I was leading a field trip through Germany. We spent a day at the Messel site and I'll post some photos of it soon.