Theiophytalia
Encyclopedia
Theiophytalia is a genus
of herbivorous iguanodont
ian dinosaur
from the lower Cretaceous
period (Aptian
-Albian
stage, about 112 million years ago) of Colorado
.
is a park near Colorado Springs, Colorado, where a skull, the only fossil of the genus yet to be discovered, was found in 1878. The specific name kerri honors James Hutchinson Kerr, who found the specimen.
The holotype
and only known specimen, YPM 1887, is a partial skull
that was referred by O.C. Marsh
(affirmed by Gilmore
, 1909), to whom the skull was given in 1886, as that of Camptosaurus
amplus. Gilmore used the skull to reconstruct the skull of Camptosaurus assuming that it came from the Morrison Formation
. However, microscopic comparisons of thin-sections of the Mesozoic formations in the Garden of the Gods
showed that the specimen actually came from the Lytle Member of the Purgatoire Formation; therefore, the skull was Early Cretaceous in age.
Detailed comparisons by Brill and Carpenter (2006) also showed that the skull differed in a number of key features from that of Camptosaurus, namely: a longer, heavier, and more rugose snout; a wider dorsal process on the maxilla; a proportionally smaller antorbital fenestra
; and stouter quadrate
, with a bulbous articulation for the lower jaw. Compare the skull image with that of Camptosaurus
. Therefore, they put it into its own genus and species.
The article describing the find classified Theiophytalia as intermediate in derivation between Camptosaurus and Iguanodon
. The type species
is Theiophytalia kerri. In 2010 and 2011 cladistic analyses of McDonald and colleagues, Theiophytalia has been recovered as a basal member of the Styracosterna and its closest relative was Hippodraco
.
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 iguanodont
Iguanodont
Iguanodonts were herbivorous dinosaurs that lived from the mid-Jurassic to Late Cretaceous. Some members include Camptosaurus, Callovosaurus, Iguanodon, Ouranosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodonts were one of the first groups of dinosaurs to be found...
ian 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...
from the lower Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period (Aptian
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous epoch or series and encompasses the time from 125.0 ± 1.0 Ma to 112.0 ± 1.0 Ma , approximately...
-Albian
Albian
The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...
stage, about 112 million years ago) of Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
.
Etymology
The generic name is, from Greek, theios: "divine" + Greek phytalia: "garden", or "garden of the gods". Garden of the GodsGarden of the Gods
Garden of the Gods is a public park located in Colorado Springs, Colorado, USA.-Genesis of the park:Entrance to the park is free according to the wish of Charles Elliott Perkins, whose children donated the land to the city of Colorado Springs in 1909....
is a park near Colorado Springs, Colorado, where a skull, the only fossil of the genus yet to be discovered, was found in 1878. The specific name kerri honors James Hutchinson Kerr, who found the specimen.
Discovery and Description
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...
and only known specimen, YPM 1887, is a partial 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...
that was referred by O.C. Marsh
Othniel Charles Marsh
Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...
(affirmed by Gilmore
Charles W. Gilmore
Charles Whitney Gilmore was an American paleontologist, who named dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus and...
, 1909), to whom the skull was given in 1886, as that of Camptosaurus
Camptosaurus
Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America. The name means 'flexible lizard', ....
amplus. Gilmore used the skull to reconstruct the skull of Camptosaurus assuming that it came from the Morrison Formation
Morrison Formation
The Morrison Formation is a distinctive sequence of Late Jurassic sedimentary rock that is found in the western United States, which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone and limestone and is light grey, greenish...
. However, microscopic comparisons of thin-sections of the Mesozoic formations in the Garden of the Gods
Garden of the Gods
Garden of the Gods is a public park located in Colorado Springs, Colorado, USA.-Genesis of the park:Entrance to the park is free according to the wish of Charles Elliott Perkins, whose children donated the land to the city of Colorado Springs in 1909....
showed that the specimen actually came from the Lytle Member of the Purgatoire Formation; therefore, the skull was Early Cretaceous in age.
Detailed comparisons by Brill and Carpenter (2006) also showed that the skull differed in a number of key features from that of Camptosaurus, namely: a longer, heavier, and more rugose snout; a wider dorsal process on the maxilla; a proportionally smaller antorbital fenestra
Antorbital fenestra
An antorbital fenestra is an opening in the skull, in front of the eye sockets. This skull formation first appeared in archosaurs during the Triassic Period. Living birds today possess antorbital fenestrae, but the feature has been lost in modern crocodilians...
; and stouter quadrate
Quadrate bone
The quadrate bone is part of a skull in most tetrapods, including amphibians, sauropsids , and early synapsids. In these animals it connects to the quadratojugal and squamosal in the skull, and forms part of the jaw joint .- Evolutionary variation :In snakes, the quadrate bone has become elongated...
, with a bulbous articulation for the lower jaw. Compare the skull image with that of Camptosaurus
Camptosaurus
Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America. The name means 'flexible lizard', ....
. Therefore, they put it into its own genus and species.
The article describing the find classified Theiophytalia as intermediate in derivation between Camptosaurus and Iguanodon
Iguanodon
Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...
. 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 Theiophytalia kerri. In 2010 and 2011 cladistic analyses of McDonald and colleagues, Theiophytalia has been recovered as a basal member of the Styracosterna and its closest relative was Hippodraco
Hippodraco
Hippodraco is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the Lower Cretaceous period in what is now Utah, USA...
.