Lycorhinus
Encyclopedia
Lycorhinus is a genus
of heterodontosaurid
ornithischia
n dinosaur
hailing from the Early Jurassic
(Hettangian
to Sinemurian
ages) strata of the Elliot Formation
located in the Cape Province
, South Africa
.
The fossil remains consist in dentaries and maxilla
e, hence the characters mentioned by the name Lycorhinus angustidens that Sidney H. Haughton
attributed to them in 1924, where the generic name means "wolf snout", as it was at first misidentified as a cynodont
, and the specific descriptor means "constricted tooth".
The holotype
, SAM 3606, consists of a mandible found by Dr M. Ricono.
Three other species of Lycorhinus have been named. Lycorhinus parvidens was created by Robert Broom
and Lycorhinus tucki by Richard Anthony Thulborn in 1970 renaming Heterodontosaurus
tucki, but these have failed to find recognition. Lycorhinus consors, named by Thulborn in 1974, was renamed Abrictosaurus
by James Hopson
in 1975.
Lycorhinus, including the remains described by Gow in 1975 as Lanasaurus, is a small (1.2 metres (47.2 in) in length) herbivorous dinosaur despite the long canine
s it sported in its jaws; in view of this typical characteristic L. angustidens is very clearly allied to Heterodontosaurus. Only in 1962 Alfred Walter Crompton recognised it was an ornithischian dinosaur. Thulborn in 1971 created a separate Lycorhinidae but this group was in 1972 equated with Heterodontosauridae
by Peter Galton
.
and only species of Lanasaurus is L. scalpridens, described by Christopher Gow in 1975 from the same horizon as Lycorhinus. The generic name is derived from Latin
lana, "wool", and honours Professor Alfred Walter Crompton, nicknamed "Fuzz" because of his woolly hair and saurus, "lizard". The specific name is derived from Latin scalprum, "chisel", and dens, "tooth". It is based on a partial upper jaw bone, the maxilla
, holotype
BP/1/4244, found in the Upper Elliot Formation
of Free State
. The teeth show a typical replacement pattern in which during each replacement cycle every third tooth is renewed.
Gow himself in 1990 concluded that the holotype of Lanasaurus was actually a specimen of Lycorhinus angustidens. This has been commonly accepted since.
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 heterodontosaurid
Heterodontosauridae
Heterodontosauridae is a family of early ornithischian dinosaurs that were likely among the most basal members of the group...
ornithischia
Ornithischia
Ornithischia or Predentata is an extinct order of beaked, herbivorous dinosaurs. The name ornithischia is derived from the Greek ornitheos meaning 'of a bird' and ischion meaning 'hip joint'...
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...
hailing from the Early Jurassic
Early Jurassic
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...
(Hettangian
Hettangian
The Hettangian is the earliest age or lowest stage of the Jurassic period of the geologic timescale. It spans the time between 199.6 ± 0.6 Ma and 196.5 ± 1 Ma . The Hettangian follows the Rhaetian and is followed by the Sinemurian.In Europe stratigraphy the Hettangian is a part of the time span in...
to Sinemurian
Sinemurian
In the geologic timescale, the Sinemurian is an age or stage in the Early or Lower Jurassic epoch or series. It spans the time between 196.5 ± 2 Ma and 189.6 ± 1.5 Ma...
ages) strata of the Elliot Formation
Elliot Formation
The Elliot Formation is a geological formation dating to roughly 210 to 190 million years ago and covering the Norian to Sinemurian stages. The Elliot Formation is found in South Africa and Lesotho and is a member of the Stormberg Group. It consists mainly of limestone, sandstone, and mudstone...
located in the Cape Province
Cape Province
The Province of the Cape of Good Hope was a province in the Union of South Africa and subsequently the Republic of South Africa...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
.
The fossil remains consist in dentaries and 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...
e, hence the characters mentioned by the name Lycorhinus angustidens that Sidney H. Haughton
Sidney H. Haughton
Sidney Henry Haughton, , was an English-born South African paleontologist and geologist. The eldest of three children born to Henry Charles Haughton and Alice Aves, he is best-known for his description of the sauropodomorph dinosaur Melanorosaurus in 1924, and his work on the geology of the...
attributed to them in 1924, where the generic name means "wolf snout", as it was at first misidentified as a cynodont
Cynodont
Cynodontia or cynodonts are a taxon of therapsids which first appeared in the Late Permian and were eventually distributed throughout all seven continents by the Early Triassic . This clade includes modern mammals and their extinct close relatives. They were one of the most diverse groups of...
, and the specific descriptor means "constricted tooth".
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...
, SAM 3606, consists of a mandible found by Dr M. Ricono.
Three other species of Lycorhinus have been named. Lycorhinus parvidens was created by Robert Broom
Robert Broom
Professor Robert Broom was a Scottish South African doctor and paleontologist. He qualified as a medical practitioner in 1895 and received his DSc in 1905 from the University of Glasgow...
and Lycorhinus tucki by Richard Anthony Thulborn in 1970 renaming Heterodontosaurus
Heterodontosaurus
Heterodontosaurus is a genus of small herbivorous dinosaur with prominent canine teeth which lived in the Early Jurassic of South Africa. It was similar to a hypsilophodont in shape, and ate plants, despite its canines.Heterodontosaurus is currently known from specimens of the SAFM from South...
tucki, but these have failed to find recognition. Lycorhinus consors, named by Thulborn in 1974, was renamed Abrictosaurus
Abrictosaurus
Abrictosaurus is a genus of heterodontosaurid dinosaur from the Early Jurassic Period of what is now southern Africa. It was a small bipedal herbivore or omnivore, approximately 1.2 meters long, and weighing less than 45 kilograms .This dinosaur is known from the fossil remains of only...
by James Hopson
James Hopson
James Allen Hopson is an American paleontologist and professor at the University of Chicago. His work has focused on the evolution of the synapsids , and has been focused on the transition from basal synapsids to mammals, from the late Paleozoic through the Mesozoic Eras...
in 1975.
Lycorhinus, including the remains described by Gow in 1975 as Lanasaurus, is a small (1.2 metres (47.2 in) in length) herbivorous dinosaur despite the long canine
Canine tooth
In mammalian oral anatomy, the canine teeth, also called cuspids, dogteeth, fangs, or eye teeth, are relatively long, pointed teeth...
s it sported in its jaws; in view of this typical characteristic L. angustidens is very clearly allied to Heterodontosaurus. Only in 1962 Alfred Walter Crompton recognised it was an ornithischian dinosaur. Thulborn in 1971 created a separate Lycorhinidae but this group was in 1972 equated with Heterodontosauridae
Heterodontosauridae
Heterodontosauridae is a family of early ornithischian dinosaurs that were likely among the most basal members of the group...
by Peter Galton
Peter Galton
Peter M. Galton is a British vertebrate paleontologist working in America, who has to date written or co-written about a hundred papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosauropod dinosaurs.With Robert Bakker in a joint article...
.
Lanasaurus
The typeType 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...
and only species of Lanasaurus is L. scalpridens, described by Christopher Gow in 1975 from the same horizon as Lycorhinus. The generic name is derived from Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
lana, "wool", and honours Professor Alfred Walter Crompton, nicknamed "Fuzz" because of his woolly hair and saurus, "lizard". The specific name is derived from Latin scalprum, "chisel", and dens, "tooth". It is based on a partial upper jaw bone, the 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...
, 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...
BP/1/4244, found in the Upper Elliot Formation
Elliot Formation
The Elliot Formation is a geological formation dating to roughly 210 to 190 million years ago and covering the Norian to Sinemurian stages. The Elliot Formation is found in South Africa and Lesotho and is a member of the Stormberg Group. It consists mainly of limestone, sandstone, and mudstone...
of Free State
Free State
The Free State is a province of South Africa. Its capital is Bloemfontein, which is also South Africa's judicial capital. Its historical origins lie in the Orange Free State Boer republic and later Orange Free State Province. The current borders of the province date from 1994 when the Bantustans...
. The teeth show a typical replacement pattern in which during each replacement cycle every third tooth is renewed.
Gow himself in 1990 concluded that the holotype of Lanasaurus was actually a specimen of Lycorhinus angustidens. This has been commonly accepted since.