Shares many features with other apes indicating a

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shares many features with other apes indicating a suspensory past. Parsimony suggests that the last common ancestor of all modern apes must have been suspensory as well. However, the 1
Early Miocene ape fossil record subverts this expectation, suggesting instead that the locomotor behaviors of modern apes were achieved independently in several different groups. Station 1: The Paleocene – Plesiadapiforms, the Stem Primates (2 pt.) The Order Primates includes all living primates and their extinct relatives back to the last common ancestor of strepsirrhines and haplorhines (“crown primates”). It also includes the now extinct plesiadapiforms (“stem primates”). Although plesiadapiforms are not the direct ancestors of living primates, their close relationship with the last common ancestor of living primates can tell us important information about early primate traits. (See the figure on Page 1.) 1. Compare and record the dental formulae of the plesiadapiform cast and the galago (a strepsirrhine). ( Note: the plesiadapiform has procumbent incisors (not a toothcomb) and the galago has a toothcomb which includes its 1 st canine.)
2. Look at the handout on the plesiadapiform Carpolestes simpsoni . Does the hallux (big toe) of Carpolestes have more symplesiomorphic features shared with the tree shrew, or synapomorphic features shared with the euprimate? List at least one feature you considered. 2
Station 2: The Eocene – Early Crown Primates (1 pt.) Two extinct superfamilies, Adapoidea and Omomyoidea, group the earliest crown primates. Adapoids are thought to be ancestral to present day strepsirrhines, while omomyoids are most likely ancestral to tarsiers and anthropoids. Many species of adapoids and omomyoids were sympatric (lived in the same place and time) and have been found throughout North America and Europe. Compare the adapoid skull with the lemur and omomyoid skull with the tarsier. Use your handouts to see the fossil skulls. Lemur: Tarsier: 1. List two traits the adapoid and the lemur share. A. __________________________________________________________________ B. __________________________________________________________________

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