Agujaceratops
Encyclopedia
Agujaceratops is a genus
of herbivorous ceratopsia
n dinosaur
. It is a chasmosaurine
ceratopsian which lived during the Late Cretaceous
period (late Campanian
stage
) in what is now Texas
. Originally known as Chasmosaurus
mariscalensis and described by Lehman in 1989
, it was moved to a new genus by Lucas, Sullivan and Hunt in 2006. Lehman felt the habitat Agujaceratops lived in (at least where the fossil material was found) may have been a swamp, due to the nature of the sediments.
In 1938, three dinosaur bone beds were excavated, and ceratopsian material was collected from Big Bend National Park
by William Strain. This material was studied by Lehman in 1989 and named Chasmosaurus mariscalensis. It is known only from the holotype
UTEP P.37.7.086 a partial adult skull
which includes a braincase, left supraorbital horncore, left maxilla
and a right dentary. Additional material was associated with the holotype, but not considered to be part of it. All specimens of Agujaceratops were collected from the upper part of the Aguja Formation
, dating to 75-73.5 million years ago, in the Big Bend National Park
, Brewster County. Subsequent analysis resulted in the taxon being put in its own genus. Agujaceratops was named by Spencer G. Lucas, Robert M. Sullivan and Adrian Hunt in 2006
and the type species
is Agujaceratops mariscalensis. Agujaceratops is similar to both Pentaceratops
and Chasmosaurus
. Its short frill suggests it probably wasn't an ancestor of Pentaceratops.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of herbivorous ceratopsia
Ceratopsia
Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs which thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7...
n dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
. It is a chasmosaurine
Chasmosaurinae
Chasmosaurinae is a subfamily of ceratopsid dinosaurs. Triceratops is a well-known example. They were one of the most successful groups of herbivores of their time. Chasmosaurines appeared in the early Campanian, and became extinct, along with all other non-avian dinosaurs, during the K-T extinction...
ceratopsian which lived during the Late Cretaceous
Late Cretaceous
The Late Cretaceous is the younger of two epochs into which the Cretaceous period is divided in the geologic timescale. Rock strata from this epoch form the Upper Cretaceous series...
period (late Campanian
Campanian
The Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
stage
Faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...
) in what is now Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
. Originally known as Chasmosaurus
Chasmosaurus
Chasmosaurus is a genus of ceratopsid dinosaur from the Upper Cretaceous Period of North America. Its name means 'opening lizard', referring to the large openings in its frill . With a length of and a weight of , Chasmosaurus was a ceratopsian of average size...
mariscalensis and described by Lehman in 1989
1989 in paleontology
-Newly named dinosaurs:Data courtesy of George Olshevsky's dinosaur genera list and Dr. Jeremy Montague's dinosaur genus database.-New taxa:-New taxa:-Non-mammalian:-References:...
, it was moved to a new genus by Lucas, Sullivan and Hunt in 2006. Lehman felt the habitat Agujaceratops lived in (at least where the fossil material was found) may have been a swamp, due to the nature of the sediments.
Discovery and species
Big Bend National Park
Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...
by William Strain. This material was studied by Lehman in 1989 and named Chasmosaurus mariscalensis. It is known only from the holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
UTEP P.37.7.086 a partial adult skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
which includes a braincase, left supraorbital horncore, left maxilla
Maxilla
The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper...
and a right dentary. Additional material was associated with the holotype, but not considered to be part of it. All specimens of Agujaceratops were collected from the upper part of the Aguja Formation
Aguja Formation
The Aguja Formation is a geological formation in North America, exposed in Texas, whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.-Ammonites:-Crurotarsans:...
, dating to 75-73.5 million years ago, in the Big Bend National Park
Big Bend National Park
Big Bend National Park is a national park located in the U.S. state of Texas. Big Bend has national significance as the largest protected area of Chihuahuan Desert topography and ecology in the United States, which includes more than 1,200 species of plants, more than 450 species of birds, 56...
, Brewster County. Subsequent analysis resulted in the taxon being put in its own genus. Agujaceratops was named by Spencer G. Lucas, Robert M. Sullivan and Adrian Hunt in 2006
2006 in paleontology
-Insects:-Tetrapodomorphs:-Newly named temnospondylians:-Newly named amphibians:-Ichthyosaurs:-Newly named basal lepidosauromorphs:-Newly named plesiosaurs:-Newly named squamates:-Newly named crurotarsans:-Newly named dinosaurs:...
and the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Agujaceratops mariscalensis. Agujaceratops is similar to both Pentaceratops
Pentaceratops
Pentaceratops is a genus of ceratopsid dinosaur from the late Cretaceous Period of what is now North America. The appearance of Pentaceratops sternbergii in the fossil record marks the end of the Judithian land vertebrate age and the start of the Kirtlandian...
and Chasmosaurus
Chasmosaurus
Chasmosaurus is a genus of ceratopsid dinosaur from the Upper Cretaceous Period of North America. Its name means 'opening lizard', referring to the large openings in its frill . With a length of and a weight of , Chasmosaurus was a ceratopsian of average size...
. Its short frill suggests it probably wasn't an ancestor of Pentaceratops.