''Acantholipan'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of herbivorous

nodosaurid Nodosauridae is a family of ankylosaurian dinosaurs, from the Late Jurassic to the Late Cretaceous period in what is now North America, South America, Europe, and Asia. Description Nodosaurids, like their close relatives the ankylosaurids, wer ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

from

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

from the early Santonian age of the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

. It includes one species, ''Acantholipan gonzalezi.''

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 Coahuila (), formally Coahuila de Zaragoza (), officially the Free and Sovereign State of Coahuila de Zaragoza ( es, Estado Libre y Soberano de Coahuila de Zaragoza), is one of the 32 states of Mexico. Coahuila borders the Mexican states of N ...

, 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. Later it was judged that the remains were sufficiently distinct to be given a

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

. In 2018, the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Acantholipan gonzalezi'' was named by Héctor Eduardo Rivera-Sylva,

Eberhard Frey Eberhard is an old Germanic name meaning the strength or courage of a wild boar. People First name *Eberhard of Friuli (815–866), Duke and key figure in the Carolingian Empire *Eberhard of Béthune (died 1212), Flemish grammarian *Eberhard I, Du ...

Wolfgang Stinnesbeck Wolfgang is a German name, German male given name traditionally popular in Germany, Austria and Switzerland. The name is a combination of the Old High German words ''wikt:wolf#Old High German, wolf'', meaning "wolf", and ''wikt:gang#Old High Germa ...

, Gerardo Carbot-Chanona, Iván Erick Sanchez-Uribe and José Rubén Guzmán-Gutiárrez. The generic name combines a Greek ''akanthos'', "spine", with ''lipan'', the usual Spanish designation of the '' Lépai-Ndé'', the "Gray People", a tribe of the

Apache The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño an ...

inhabiting the area of the find. The specific name honours the Mexican

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

Arturo Homero González-González, the chairman of the '' Museo del Desierto'' at

Saltillo Saltillo () is the capital and largest city of the northeastern Mexican state of Coahuila and is also the municipal seat of the municipality of the same name. Mexico City, Monterrey, and Saltillo are all connected by a major railroad and highwa ...

. ''Acantholipan'' is the first ankylosaurian species named from Mexico. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen, CPC 272, was found alongside another nodosaur, CPC 273, in a marine layer of the Pen Formation and dates from the

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...

. 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 The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

, an upper left

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

, the underside of the left

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

and a spike-like

osteoderm Osteoderms are bony deposits forming scales, plates, or other structures based in the dermis. Osteoderms are found in many groups of extant and extinct reptiles and amphibians, including lizards, crocodilians, frogs, temnospondyls (extinct amp ...

probably from the posterior

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

. The fossil is part of the ''Colección Paleontológica de Coahuila, Museo del Desierto, Saltillo''.

Classification

''Acantholipan'' belongs to the

Nodosaurinae Nodosaurinae is a subfamily of nodosaurid ankylosaurs from the Cretaceous of Europe, North America, and South America. The group is defined as the largest clade containing '' Nodosaurus textilis'' but not ''Hylaeosaurus armatus'', '' Mymoorapelta ...

and is the sister taxon to ''

Nodosaurus ''Nodosaurus'' (meaning "knobbed lizard") is a genus of herbivorous nodosaurid ankylosaurian dinosaur from the Late Cretaceous, the fossils of which are found exclusively in the Frontier Formation in Wyoming. Description ''Nodosaurus'' grew ...

''. The

2018 File:2018 Events Collage.png, From top left, clockwise: The 2018 Winter Olympics opening ceremony in PyeongChang, South Korea; Protests erupt following the Assassination of Jamal Khashoggi; March for Our Lives protests take place across the United ...

phylogenetic analysis of Rivera-Sylva and colleagues is below:

References

Late Cretaceous dinosaurs Ankylosaurs Fossil taxa described in 2018 Fossils of Mexico Ornithischian genera {{Ankylosaurian stub

Discovery and naming

Classification

See also

References