A docodontan mammaliaform from the Middle Jurassic of China possesses swimming and burrowing skeletal adaptations and some dental features for aquatic feeding. It is the most primitive taxon in the mammalian lineage known to have fur and has a broad, flattened, partly scaly tail analogous to that of modern beavers. We infer that docodontans were semiaquatic, convergent to the modern platypus and many Cenozoic placentals. This fossil demonstrates that some mammaliaforms, or proximal relatives to modern mammals, developed diverse locomotory and feeding adaptations and were ecomorphologically different from the majority of generalized small terrestrial Mesozoic mammalian insectivores.
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Materials and methods are available as supporting material on Science Online.
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We thank Z.-Y. Sun and the Jinzhou Museum of Paleontology for making this specimen available for us to study. We also thank K. C. Beard, M. R. Dawson, T. Martin, N. Rybczynski, and J. R. Wible for numerous discussions; M. R. Dawson for improving the manuscript; M. A. Klingler for assistance with graphics; J. R. Wible for access to collections; and H.-L. You for assistance with this study. We received support from the Chinese Academy of Geological Sciences (Beijing), Ministry of Land Resources of China, Ministry of Science and Technology of China (973 project) (Q.J.); and from the National Science Foundation (USA), National Natural Science Foundation (China), National Geographic Society, and Carnegie Museum of Natural History (Z.-X.L.).
Volume 311 | Issue 5764
24 February 2006
24 February 2006
American Association for the Advancement of Science.
Received: 28 November 2005
Accepted: 23 January 2006
Published in print: 24 February 2006
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