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Iguanodontian dinosaurs from Lower Cretaceous of Tunisia



Ben Creisler
bcreisler@gmail.com


A new paper:


Federico Fanti, Andrea Cau, Lukas Panzarin & Luigi Cantelli (2016)
Evidence of iguanodontian dinosaurs from the Lower Cretaceous of Tunisia.
Cretaceous Research 60: 267–274
doi:10.1016/j.cretres.2015.12.008
http://www.sciencedirect.com/science/article/pii/S0195667115301336



Highlights

In this study we describe isolated iguanodontians teeth from the
Albian of Tunisia.

Teeth occur in the Albian coastal deposits of the Ain el Guettar Formation.

Iguanodontians are associated with spinosaurids, rebbachisaurids and
crocodilians.

Taphonomic analyses challenges paleoecologic distribution of isolated
Saharan dinosaurs.

Abstract

The fossil record of ornithischian dinosaurs from Africa is
particularly scarce and limited to a few historic localities. In this
study we describe new ornithischian remains from the Albian deposits
of southern Tunisia (Tataouine Governorate), represented by isolated
teeth of large-bodied iguanodontians. Teeth display a wide,
diamond-shaped crown with a primary ridge dividing the occlusal
surface in two unequal parts and two or more secondary ridges.
Hook-like denticles are present on both mesial and distal crown
margins and do not display mammillae. In overall morphology, specimens
are comparable to those of many Early Cretaceous basal
hadrosauriforms, including isolated ornithopodan teeth from
comparably-aged levels of Niger. Transversal sections of the crowns
permitted identification of dental tissues, which include a thick
enamel, and well developed longitudinal and transverse giant tubules.
Their relative extents appear to be related to the size, thus
developmental age, of the tooth. Teeth are representative of the Oum
ed Diab Member, a unit characterized by coastal deposits accumulated
under arid to xeric climatic conditions and dominated by fish,
crocodilians, and hydraulically transported rebbachisaurid and
spinosaurid remains. Sedimentological data and preservation bias
strongly support selective taphonomic causes for the fossil
distribution of ornithischians in southern Tunisia questioning the
purported geographic and paleoecologic distribution of isolated
Saharan dinosaurs.