Revision of the Paleogene genus Glyptosaurus (Reptilia, Anguidae). Bulletin of the AMNH ; v. 163, article 1

72 p. : ill., map ; 26 cm.Includes bibliographical references (p. 69-72)."The Paleogene North American lizard Glyptosaurus (Reptilia, Anguidae) Marsh, 1871 is revised. Two new genera, Eoglyptosaurus and Paraglyptosaurus, are named. Helodermoides Douglass, 1903 is resurrected as a valid genus. Glyptosaurus (sensu stricto) is known by one species, G. sylvestris; G. nodosus is placed in the synonymy of G. sylvestris from Grizzly Buttes, Wyoming (middle Eocene). The new genus Paraglyptosaurus (early-middle Eocene) includes the species P. princeps (Marsh, 1872), including as synonyms G. rugosus and G. hillsi. Paraglyptosaurus yatkolai, new species is based on a single frontal from the Wasatchian of New Mexico. Glyptosaurus donohoei White, 1952 is referred to a new genus, Eoglyptosaurus (early Eocene). Two species of Glyptosaurus (sensu lato) are considered nomina dubia: Glyptosaurus sphenodon Marsh, 1872 and Glyptosaurus obtusidens Loomis 1907. Glyptosaurus montanus and Glyptosaurus giganteus are synonyms of Helodermoides tuberculatus Douglass 1903 (early-middle Oligocene). The late Eocene Mongolian Glyptosaurus near nodosus Gilmore, 1943 is transferred to Helodermoides as a new species, H. mongoliensis. The late Eocene European species Placosaurus Gervais, 1852, its type P. rugosus, Placosaurus waltheri (Weigelt, 1929), and Placotherium waltheri (Weigelt, 1929) are considered nomina dubia. Two tribes are designated: the tribe Glyptosaurini to include Eoglyptosaurus, Paraglyptosaurus, Glyptosaurus, and Helodermoides and the tribe Melanosaurini to include the other glyptosaurines Melanosaurus, Arpadosaurus, Peltosaurus, and Xestops. The subfamily Glyptosaurinae is the most primitive subfamily of the Anguidae, and the subfamily Anguinae is the most derived based on dermal armor morphology, mandibular length, palatal teeth, presence or absence of limbs, presence or absence of premaxillary fenestrae, the nature of the postorbital-postfrontal association, and the state of fusion of various skeletal elements. The tribe Melanosaurini is the most primitive tribe of the subfamily Glyptosaurinae and the tribe Glyptosaurini is the most derived based on the morphology of the epidermal scale impressions upon the dermal armor. Helodermoides is viewed as the most derived glyptosaurinid and glyptosaurine. The primitive nature of Helodermoides is regarded as paedomorphic owing to its late occurrence. The tribe Gly[p]tosaurini as a whole is regarded as a paedomorphic lineage primarily based upon the disintegration of dermal armor into discrete hexagonal osteoderms. Because of the primitive nature of Odaxosaurus it is removed from the subfamily Anguinae and designated Anguidae: incertae sedis"--P. 5