1999. Journal of Vertebrate Paleontology, Abstracts of Papers, 19(3):34.
A BIZARRE NEW CROCODYLIFORM FROM THE LATE CRETACEOUS OF MADAGASCAR
BUCKLEY, Gregory A., ETSUC, Roosevelt University, Chicago, IL 60605; BROCHU, Christopher A., Department of Geology, Field Museum of Natural History, Chicago IL 60605; RANDRIAMIARAMANANA, Louis L., Service de Paleontologie, Universite d'Antananarivo, Antananarivo (101), Madagascar; KRAUSE, David W., Department of Anatomical Sciences, SUNY, Stony Brook, NY 11794.
A new crocodyliform was discovered in 1998 in the Upper Cretaceous Maevarano
Formation of northwestern Madagascar. This specimen, the anterior half of which
is preserved in exquisite condition, represents the seventh crocodyliform
species known from the faunal assemblage.
Several aspects of the morphology of the new form are unique
among crocodyliforms. A pair of osteoderms roof the supratemporal fenestrae. The
snout is very broad, strongly compressed mesiodistally and tall dorsoventrally,
resembling that of a turtle in proportions. The jaw articulation is shifted
anteriorly, indicating that the functional mechanics of the jaw differ
significantly from those of other crocodyliforms. The lower jaws have a strong
flange formed by a laterally projecting angular, similar to the structure in the
crocodyloid Mekosuchus.
The dentition is also unlike that of any other known
crocodyliform. The teeth are strongly compressed laterally with multiple cusps
in a single mesiodistal row. The anterior teeth are also compressed and
multicuspate, unlike the condition in Malawisuchus and Chimaerasuchus,
which have multicuspate posterior teeth but typical conical teeth in the
premaxilla and anterior dentary. Additionally, in these other two taxa the
multiple cusps are in more than one single row, somewhat resembling a mammalian
condition. The teeth of the Madagascar species more closely resemble those of
some ornithischian dinosaurs. A large antorbital fenestra suggests a
relationship with the notosuchids, a predominantly South American group of
metasuchian crocodyliforms.