JS23 - Unique Undescribed Basal Spinosaurid Dinosaur Tooth Jurassic Tiouraren Fm

Scientific name: Undescribed basal Spinosaurid

Location: Tiouraren Hill, Téneré Desert, Niger.

Geological Formation: Tiouraren Fm

Age: Middle Jurassic, Bathonian stage ( 167 million years)

Size (long): 4.2cm = 1.67 Inch

REF.: JS23

DESCRIPTION:
Here we present a true rarity. It is a theropod dinosaur tooth with some remarkable peculiarities. It is a premaxillary tooth, but it has a series of well-marked longitudinal striations, characteristic of Spinosaurids. However, the morphology and strong lateral serrations are still reminiscent of normal theropods. Therefore, we can deduce that this tooth must have belonged to a basal taxon of the spinosaurid group, which began to specialize in an ichthyophagous diet in the Jurassic, with these basal forms. Unfortunately these geological formations are quite poorly studied and we cannot assign this tooth to a specific taxon. However, we can ensure that it is a hybrid morphotype between normal theropods and the first spinosaurids.

The Tiouraren Formation is a geological formation in the Agadez Region of Niger whose strata were originally thought to be Early Cretaceous. However, re-interpretation of the sediments showed that they are probably Middle Jurassic (Bathonian) in age. It is the uppermost unit of the Irhazer Group. Dinosaur remains are among the fossils that have been recovered from the formation.

The formation comprises reddish, almost solid mudstones. The depositional environment has been interpreted as swampy with seasonal flooding in braided river systems.