Glyptosaurinae

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Glyptosaurinae
Temporal range: Late Cretaceous - Paleogene
Helodermoides tuberculatus AMNH 11311.jpg
Fossil of the glyptosaurine Helodermoides tuberculatus
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Anguidae
Subfamily: Glyptosaurinae
Marsh, 1872
Subgroups
Skull of the glyptosaurine Peltosaurus

Glyptosaurinae is an extinct subfamily of anguid lizards that lived in the Northern Hemisphere during the Late Cretaceous and the Paleogene. Glyptosaurines are known primarily from their osteoderms, scale-like pieces of bone that are embedded in the skin and cover much of their bodies. The shape and extent of the osteoderms in glyptosaurines are similar to those seen in an unrelated group of lizards called Monstersauria, which includes the living Gila monster and beaded lizard.[1] The osteoderms of glyptosaurines are unusually complex, consisting of four distinct layers of bony tissue. These tissues may have derived from both the dermis (the lower layer of the skin) and the epidermis (the outer layer of the skin) during their development in the embryo. The tissue forming the outermost layer of glyptosaurine osteoderms is similar to tooth enamel and has even been given its own name, osteodermine.[2]

Glyptosaurines have been split into the subgroups Melanosaurini and Glyptosaurini, although recent phylogenetic analyses show that Melanosaurini in its traditional sense is paraphyletic, representing an evolutionary grade of glytosaurines more basal ("primitive") than Glyptosaurini. Below is a cladogram from Conrad and Norell (2008) showing the interrelationships of glyptosaurines and their relationship to other anguid lizards:[1]

Anguimorpha

Carusioidea


Anguidae

Diploglossinae



Glyptosaurinae

Odaxosaurus piger





Proxestops jepseni



Xestops vagans






Paraplacosauriops quercyi



Peltosaurus granulosus




Melanosaurini (sensu stricto)

Arpadosaurus gazinorum



Melanosaurus maximus



Glyptosaurini

Glyptosaurus sylvestris



Placosaurus rugosus




Proglyptosaurus huerfanensis




Paraglyptosaurus princeps




Helodermoides tuberculatus




Placosaurus estesi



Placosaurus mongoliensis













Anguinae



Gerrhonotinae






References[edit]

  1. ^ a b Conrad, J. L.; Norell, M. A. (2008). "The braincases of two glyptosaurines (anguidae, Squamata) and anguid phylogeny". American Museum Novitates 3613: 1. doi:10.1206/586.1.  edit
  2. ^ De Buffrénil, V.; Dauphin, Y.; Rage, J. C.; Sire, J. Y. (2011). "An enamel-like tissue, osteodermine, on the osteoderms of a fossil anguid (Glyptosaurinae) lizard". Comptes Rendus Palevol 10 (5–6): 427. doi:10.1016/j.crpv.2011.03.010.  edit