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[dinosaur] Fwd: Dicothodon, tooth replacement in borioteiioid lizard from Late Cretaceous of Baja California, Mexico (free pdf)

Apparently another blocked post... I tried sending this earlier but I don't see it in my email. Apologies for the resend if some people got it the first time or it shows up later.

---------- Forwarded message ----------
From: Ben Creisler <bcreisler@gmail.com>
Date: Thu, Jul 19, 2018 at 11:03 AM
Subject: Dicothodon, tooth replacement in borioteiioid lizard from Late Cretaceous of Baja California, Mexico (free pdf)
To: dinosaur-l@usc.edu

Ben Creisler

A new paper in open access:

MarÃa Luisa Chavarria-Arellano, Tiago R. Simoes, and Marisol Montellano-Ballesteros (2018)Â
New data on the Late Cretaceous lizard Dicothodon bajaensis (Squamata, Borioteiioidea) from Baja California, Mexico reveals an unusual tooth replacement pattern in squamates.Â
Anais da Academia Brasileira de CiÃncias (advance online publication)

Free pdf:

Borioteiioids comprise an extinct family of squamates that inhabited the Northern Hemisphere during the Cretaceous and were characterized by varying patterns of tooth replacement and dental morphology. Understanding the evolution of these tooth replacement patterns has, however, been largely hampered by an extremely fragmentary fossil record. Here we present new information on Dicothodon bajaensisfrom the Campanian of Baja California (Mexico), so far known only from isolated teeth and jaw fragments. Among abundant new materials there are ten maxillae and five dentaries belonging to distinct ontogenetic stages. Whereas juveniles display active tooth replacement, older specimens show no evidence of replacement. Dicothodon bajaensis is therefore inferred to have had arrested tooth replacement later in ontogeny. This provides the first evidence of cessation of tooth replacement during late ontogeny in lizards (living or extinct). This replacement type is also an evolutionary intermediate between the typical lizard replacement pattern, observed in some borioteiioids (e.g., Bicuspidon) and the complete absence of tooth replacement since early ontogeny as observed in other borioteiioids (e.g., Polyglyphanodon).