Latirhinus: dinosaurs from the group of euornitopodes

Latirin (lat.: Latirhinus) is a genus of herbivorous ornithischian dinosaurs from the Euornithopoda group (Euornithopoda), which lived in the late Cretaceous period in the territory of modern Mexico. The only named species of lathyrin is Latirhinus uitstlani.

History of the find and naming

In 1987, during excavations carried out near the city of Parras de la Fuente, near the village of Presa San Antonio, an expedition of the Geological Institute of the National Autonomous University of Mexico discovered the skeleton of an unknown hadrosaurid. The found specimen was called “Isauria” (lat.: Isauria).

In 2006, this dinosaur was classified as a species of the genus Gryposaurus (lat.: Gryposaurus). However, a more detailed study turned out to be an unknown taxon, which over the next few years was identified as a representative of the subfamily Saurolophinae (lat.: Saurolophinae), who lived on the territory of the Sabinas basin.

In 2012, Mexican paleontologists Albert Prieto-Marquez and Claudia Ines Serrano Brañas gave the type species of dinosaur the Latin name Latirhinus uitstlani and described it. The generic name “Latirhinus”, derived from the Latin word “latus” (“wide”) and the ancient Greek word “ῥίς” (rhis; “nose”), indicates that this animal had a broad muzzle.

The specific epithet “uitstlani” means “southern” in Nahuatl and indicates that the dinosaur’s habitat occupied the southern part of the then-existing subcontinent of Laramidia.

holotype

The holotype, specimen no. IGM 6583, was found in the Cerro del Pueblo Formation, dating from the Upper Campanian of the Late Cretaceous.

It consists of an incomplete skeleton with skull fragments. The surviving bone material includes the right nasal bone, 10 spinal vertebrae, 14 tail vertebrae, left shoulder blade, right koicoid, both shoulder bones, both elbow bones, the third and fourth metacarpal bones of the right brush, the upper edge of the right sciatic bone, both femoral bones, both femoral bones, both femoral bones, both femoral bones Both tibia, both of the unhuman bones, leftwing bone, third and fourth metatarsal bones of both feet, the upper phalanx of the finger of the right foot and the claw of one finger of the foot.

Description

Lathyrin is a fairly large saurolophin. Its 1 meter long femur suggests that the dinosaur’s total body length was about 7 meters. A distinctive feature of the lathyrin is the presence of a high arched protrusion on its muzzle.

Other possible distinguishing features of this animal include a wide depression in front of the nostrils, as well as a forward and upward curved ridge on the shoulder blade, designed to attach the deltoid muscle.

Classification

The authors of the description attributed the lathirina to the subfamily Saurolophina as a putative close relative of the Gryposaurus, Kritosaurus (lat.: Kritosaurus) and Secernosaurus (Secernosaurus).