''Tlatolophus'' (meaning "word crest") 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 ...

hadrosaurid Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...

dinosaur belonging to the tribe

Parasaurolophini Parasaurolophini is a tribe of derived corythosaurian lambeosaurine hadrosaurids that are native to Asia, and North America. It is defined as everything closer to ''Parasaurolophus walkeri'' than to ''Lambeosaurus lambei''. It currently contain ...

. The only species is 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 ...

, ''Tlatolophus galorum''.

Discovery and naming

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 CIC/P/147, was first discovered as a semi-articulated tail in 2005 in sediments of the

Cerro del Pueblo Formation The Cerro del Pueblo Formation is a geological Formation (geology), formation in Coahuila, Mexico whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel et al., ...

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 ...

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 ...

. In 2013, the Mexican National Institute of Anthropology and History and the

National Autonomous University of Mexico The National Autonomous University of Mexico ( es, Universidad Nacional Autónoma de México, UNAM) is a public research university in Mexico. It is consistently ranked as one of the best universities in Latin America, where it's also the bigges ...

launched a joint project to recover it. It was soon realized that it belonged to the most complete

lambeosaurine Lambeosaurinae is a group of crested hadrosaurid dinosaurs. Classification Lambeosaurines have been traditionally split into the tribes or clades Parasaurolophini ('' Parasaurolophus'', ''Charonosaurus'', others (?).) and Lambeosaurini (''Cor ...

known from Mexico with an almost complete

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

, jaws, and additional parts of the

postcranial Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...

skeleton including an articulated tail. It was named as the new genus and

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

''Tlatolophus galorum'' in 2021. The generic name comes from the

Náhuatl Nahuatl (; ), Aztec, or Mexicano is a language or, by some definitions, a group of languages of the Uto-Aztecan language family. Varieties of Nahuatl are spoken by about Nahua peoples, most of whom live mainly in Central Mexico and have smaller ...

word tlatolli, meaning "word", combined with

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

''lophos'' ("crest") due to the crest's resemblance to the

glyph A glyph () is any kind of purposeful mark. In typography, a glyph is "the specific shape, design, or representation of a character". It is a particular graphical representation, in a particular typeface, of an element of written language. A g ...

"word" in

Aztec The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different Indigenous peoples of Mexico, ethnic groups of central Mexico, particularly those g ...

iconography, resembling an inverse comma. The

is named after the Garza and López families for their collaboration in collecting and preserving the specimen.

Description

The holotype specimen of ''Tlatolophus'', CIC/P/147, represents a large individual, around in length. It preserves an almost complete skull, complete with lower jaws. CIC/P/147 only lacks the

surangular The suprangular or surangular is a jaw bone found in most land vertebrates, except mammals. Usually in the back of the jaw, on the upper edge, it is connected to all other jaw bones: dentary, angular, splenial and articular The articular bone i ...

and quadrate bones. ''Tlatolophus'''s skull is relatively tall. Its

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

contacts the

nasal Nasal is an adjective referring to the nose, part of human or animal anatomy. It may also be shorthand for the following uses in combination: * With reference to the human nose: ** Nasal administration, a method of pharmaceutical drug delivery ** ...

, but only along the nasal process. The

jugal The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species. Anatomy ...

orbital margins are wider than the infratemporal margin. The frontal platform is present, being dorsocaudally extended and overhanging the parietals. The

nasal cavity The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nasal c ...

occupies the structure's entirety, including the caudal end of the supracranial crest which is comma-shaped, hence the

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 ...

. The

pterygoid bone The pterygoid is a paired bone forming part of the palate of many vertebrates, behind the palatine bone In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the th ...

possesses a high and convex dorsal crest. CIC/P/147 also preserves partial postcranial elements. The scapular neck is relatively stout, and the iliac postacetabular process is long. The ischium possesses a large ischial foot, and its tip is cranioventrally projected. A partial, articulated tail is also preserved, the first remains to be discovered of this taxon.

Classification

''Tlatolophus'' was assigned to the tribe Parasaurolophini by Ramírez-Velasco ''et al.'' in 2021. The

cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...

below displays the results of their

phylogenetic analysis In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

References

{{Taxonbar, from=Q106805159 Late Cretaceous dinosaurs of North America Lambeosaurines Fossil taxa described in 2021 Fossils of Mexico Campanian genus first appearances Campanian genus extinctions Ornithischian genera Campanian life

Discovery and naming

Description

Classification

See also

References