“Edentata” summary

INTRODUCTION Edentata was originally employed (Cuvier, 1798) to include living members of what are now recognized as three distinct mammalian clades, Xenarthra (armadillos, anteaters, sloths), Pholidota (pangolins), and Tubulidentata (aardvarks). Since that time, various combinations of these taxa, their fossil relatives, the extinct groups Palaeanodonta and Ernanodonta, and some enigmatic fossil forms have been included within Edentata (Rose et al., 2005). In general, “Edentata” is now favored as an informal term to include xenarthrans, pholidotans, and palaeanodonts, although Novacek (1986, 1992) and Novacek and Wyss (1986) have argued that a clade consisting of Pholidota and Xenarthra can be diagnosed and should be formally recognized as the cohort Edentata. GENERAL CONSIDERATIONS The North American Tertiary record of edentates consists solely of Paleocene and Eocene palaeanodonts and pangolins and late Miocene to Recent xenarthrans. A recent summary of edentates can be found in Rose et al. (2005). FEATURES UNITING “EDENTATA” As the name implies, many edentates either lack teeth completely (pholidotans, anteaters) or have reduced and simplified dentitions. When postcanine teeth are present, they are normally simple, peglike, and lack enamel coverings (except in most palaeanodonts). Edentates in general have relatively robust skeletons with specialized forelimbs adapted for digging. Forelimb specializations include humeri with long and well-developed deltopectoral crests, large medial epicondyles, robust supinator crests, ulnae with elongate, medially inflected olecranon processes, and hands with enlarged middle digits and robust claws.