Latirhinus (meaning "broad nose" from the Latin latus (broad) and Greek ῥίς, rhis (nose)) is an extinct genus of lambeosaurine hadrosaurid dinosaur from the Late Cretaceous of Mexico. The type species, Latirhinus uitstlani, was named in 2012 on the basis of a partial skeleton from the Campanian-age Cerro del Pueblo Formation. The specific name uitstlani means "southern" in the Náhuatl language of Mexico, a reference to the species' southern occurrence in the Cretaceous landmass Laramidia.

Discovery and research

During the 1980s, a team from UNAM's Geological Institute, including Shelton P. Applegate, René Hernández-Rivera, Espinosa-Arrubarrena, the SEPC team, and some volunteers, excavated the remains of a dinosaur near the town of Presa de San Antonio, belonging to the Cerro del Pueblo Formation in the Parras Basin, located in Coahuila, Mexico. The specimen was found by Don Ramón López, which was a juvenile specimen of 6 meters long, 2.2 height at the waist, and an estimated weight of 3 tons, of which 65% was recovered. This was the first dinosaur skeleton from Mexico to be mounted for public display. This specimen, though fairly complete, lacked a skull, but was identified as the saurolophine Kritosaurus sp. based on comparisons with Kritosaurus incurvimanus, which is now considered a more recent synonym of Gryposaurus notabilis. Due to its importance, the skeleton was given the informal name of "Isauria", and it is exhibited in the Museum of the Institute of Geology of the UNAM, Universum, Museo Papalote in the State of Hidalgo, Museo del Desierto, and several private parks. Serrano-Brañas, in 2006, identified one of the bones collected as a supposed nasal, and together with the appendicular skeleton, he referred to the genus Gryposaurus in his thesis.

Description

Life restoration

Latirhinus was a medium-sized hadrosaur, measuring 8.7 metres (29 ft) long and weighing around 3.75 metric tons (4.13 short tons). The holotype specimen, IGM 6583, consists of a partial skeleton including a partial right nasal, 10 dorsal and 14 caudal vertebrae, the right coracoid, left scapula, both humeri and ulna, right III and IV metacarpals, periacetabular process of Right ilium, iliac peduncle of the right ischium, both femurs, tibiae, and fibulae, left talus, right and left metatarsals III and IV, and several proximal phalanges of the right foot.

Classification

Pectoral elements

Latirhinus was originally thought to be similar to the saurolophine Gryposaurus. However, a 2012 study found its holotype, as originally defined, to be a chimera comprising both lambeosaurine and saurolophine remains; the holotype bones would've belonged to a lambeosaurine. While this position has been accepted by other researchers, there are still disagreements over where Latirhinus falls within Lambeosaurinae. The first cladogram shows Latirhinus as a basal lambeosaurine, while the second shows an alternate position as a derived member of Lambeosaurini.

LambeosaurinaeJaxartosaurus Aralosaurus Latirhinus Ajnabia Adynomosaurus Pararhabdodon Tsintaosaurus Arenysaurus Blasisaurus Canardia Parasaurolophini Tlatolophus Charonosaurus Parasaurolophus Lambeosaurini
Jaxartosaurus
Aralosaurus
Latirhinus
Ajnabia Adynomosaurus Pararhabdodon Tsintaosaurus
Ajnabia
Adynomosaurus Pararhabdodon Tsintaosaurus
Adynomosaurus
Pararhabdodon Tsintaosaurus
Pararhabdodon
Tsintaosaurus
Arenysaurus Blasisaurus Canardia Parasaurolophini Tlatolophus Charonosaurus Parasaurolophus Lambeosaurini
Arenysaurus Blasisaurus Canardia
Arenysaurus
Blasisaurus
Canardia
Parasaurolophini Tlatolophus Charonosaurus Parasaurolophus Lambeosaurini
ParasaurolophiniTlatolophus Charonosaurus Parasaurolophus
Tlatolophus
Charonosaurus
Parasaurolophus
Lambeosaurini
LambeosauriniAmurosaurus Sahaliyania Velafrons Latirhinus Magnapaulia Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp. Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Amurosaurus Sahaliyania
Amurosaurus
Sahaliyania
Velafrons Latirhinus Magnapaulia Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp. Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Velafrons
Latirhinus Magnapaulia Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp. Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Latirhinus
Magnapaulia Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp. Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Magnapaulia
Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp. Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Hypacrosaurus stebingeri Corythosaurus spp. Lambeosaurus spp.
Hypacrosaurus stebingeri
Corythosaurus spp. Lambeosaurus spp.
Corythosaurus spp.
Lambeosaurus spp.
Angulomastacator Hypacrosaurus altispinus Olorotitan Arenysaurus Blasisaurus
Angulomastacator
Hypacrosaurus altispinus
Olorotitan
Arenysaurus Blasisaurus
Arenysaurus
Blasisaurus

See also

Further reading

  • Ramírez-Velasco, Ángel Alejandro; Espinosa-Arrubarrena, Luis; Alvarado-Ortega, Jesús (May 2021). "Review of the taxonomic affinities of Latirhinus uitstlani, an emblematic Mexican hadrosaurid". Journal of South American Earth Sciences. 110 103391. Bibcode:. doi:.