Acantholipan

Acantholipan; Temporal range: Late Cretaceous, 83.6 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
	Life restoration based on Sauropelta, a possible relative
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Thyreophora
Clade:	†Ankylosauria
Family:	†Nodosauridae
Subfamily:	†Nodosaurinae
Genus:	†Acantholipan; Rivera-Sylva et al., 2018
Type species
	†Acantholipan gonzalezi; Rivera-Sylva et al. 2018

Acantholipan is a genus of herbivorous nodosaurid dinosaur from Mexico from the early Santonian age of the Late Cretaceous. It includes one species, Acantholipan gonzalezi.^[1]

Discovery and naming

In the north of Mexico, fragmentary fossils have been found of nodosaurids. A partial skeleton excavated at Los Primos near San Miguel in Coahuila, was described in 2011. When Rivera-Sylva and colleagues reported the discovery of this specimen, CPC 272, they initially considered it too fragmentary to name.^[2] Later it was judged that the remains were sufficiently distinct to be given a binomial name.

In 2018, the type species Acantholipan gonzalezi was named by Héctor Eduardo Rivera-Sylva, Eberhard Frey, Wolfgang Stinnesbeck, Gerardo Carbot-Chanona, Iván Erick Sánchez-Uribe and José Rubén Guzmán-Gutiérrez. The generic name combines a Greek akanthos, "spine", with lipán, the usual Spanish designation of the Lépai-Ndé, the "Gray People", a tribe of the Apache inhabiting the area of the find. The specific name honours the Mexican paleontologist Arturo Homero González-González, the chairman of the Museo del Desierto at Saltillo. Acantholipan is the first ankylosaurian species named from Mexico.^[1]

The holotype specimen, CPC 272, was found alongside another nodosaur, CPC 273, in a marine layer of the Pen Formation and dates from the Santonian. It consists of partial skeleton lacking the skull. Its remains include a back vertebra, a tail vertebra, a piece of a rib, the underside of the left humerus, an upper left ulna, the underside of the left femur and a spike-like osteoderm probably from the posterior thorax.^[2] The fossil is part of the Colección Paleontológica de Coahuila, Museo del Desierto, Saltillo.^[1]

Classification

Acantholipan belongs to the Nodosaurinae and is the sister taxon to Nodosaurus.^[1] The 2018 phylogenetic analysis of Rivera-Sylva and colleagues is below:^[1]