Scleroglossa

From Palaeos

  SQUAMATA
  |
  Scleroglossa
  |--+--+--Amphisbaena
  |  |  `--Gekkota
  |  `--+--Scincomorpha
  |     `--Anguimorpha
  |        |--Anguoidea
  |        `--Varanoidea
  |           |--Monstersauria
  |           `--+--Necrosauridae
  |              `--+--Varanidae
  |                 `--Lanthanotidae
  PYTHONOMORPHA

Introduction

"Scleroglossa" means "hard tongue," which surely has some significance, although its a bit hard to see. Many of the members of this group have split tongues. However, the reference is probably to the notched, inelastic distal part of the tongue in anguimorphs. Since skinks, gekkos and amphisbaenids don't share this characteristic, the name is somewhat inappropriate. Since few of us think in Classical Greek, little harm is done.

The Sceroglossa includes three kinds of relatively common lizards (skinks, gekkos and varanoids), as well as the legless lizards (amphisbaenids), the mosasaurs and all of the snakes. The latter two groups will be treated in a later section. The relationships of all of these groups are not very well understood, but it is relatively clear that all are related to each other more closely than any of them are to the iguanas and their kin. For example, Michael (MSY) Lee, a well-known paleontologist, has written several papers placing the pythonomorphs (snakes and mosasaurs) among the varanoids. In this he is strongly opposed by Olivier Rieppel and co-workers. Rieppel and Lee have been head-to-head on a number of other issues, including the phylogeny of pareiasaurs, the ancestry of turtles, and the marine (Lee) or terrestrial (Rieppel) origin of snakes. Their various, often heated, disputes are chronicled in a number of places on this site. We have cautiously chosen a sort of middle ground in this particular dispute, based on the work of Michael Caldwell.

Credits

Palaeos com ATW050706.