Dystrophaeus
Encyclopedia
Dystrophaeus is the name given to an extinct genus
of dinosaur
from the early Kimmeridgian
stage of the Late Jurassic
that existed around 155.7 Ma. It was perhaps a diplodocoid sauropod. Its fossils were found in the Morrison Formation
of Utah.
The type species
, D. viaemalae, was described by Edward Drinker Cope
in 1877. The genus name means "coarse joint" from Greek dys, "bad", and stropheus, "joint", a reference to the pitted joint surfaces serving as an attachment for cartilage
. The specific name reads as Latin
viae malae, "of the bad road", a reference to the various arduous routes taken to find, reach and salvage the remains. It consists of one partial skeleton, the holotype
USNM 2364, which includes an ulna
, a 76 centimetres long humerus
, a scapula
, a partial radius
, and some metacarpals discovered in August 1859 by John Strong Newberry
. It was found in what is possibly stratigraphic zone 1 of the Morrison, although an older Oxfordian-Callovian
has also been suggested. Dystropheus represents one of the oldest discoveries of sauropods in America; earlier, in 1855, some teeth had been found of Astrodon
.
The classification of Dystrophaeus has been rather confusing. Cope in 1877 merely concluded it was some Triassic dinosaur. Henri-Émile Sauvage in 1882 understood it was a sauropod, assigning it to the Atlantosauridae. Othniel Charles Marsh
however, in 1895 stated it belonged to the Stegosauridae
. Friedrich von Huene
, the first to determine it was of Jurassic age, in 1904 created a special family for it, the Dystrophaeidae, which he assumed to be herbivorous theropods. Only in 1908 von Huene realised his mistake and classified it in the sauropod Cetiosauridae, refining this in 1927 to the Cardiodontinae. Alfred Romer
in 1966 put it in the Brachiosauridae
, in a subfamily Cetiosaurinae.
Finally, a modern analysis by David Gillette
concluded it was a member of the Diplodocidae. However, many researchers consider the taxon to be a nomen dubium
.
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 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 early Kimmeridgian
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma . The Kimmeridgian follows the Oxfordian and precedes the Tithonian....
stage of the Late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
that existed around 155.7 Ma. It was perhaps a diplodocoid sauropod. Its fossils were found in 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...
of Utah.
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...
, D. viaemalae, was described by Edward Drinker Cope
Edward Drinker Cope
Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...
in 1877. The genus name means "coarse joint" from Greek dys, "bad", and stropheus, "joint", a reference to the pitted joint surfaces serving as an attachment for cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
. The specific name reads as 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...
viae malae, "of the bad road", a reference to the various arduous routes taken to find, reach and salvage the remains. It consists of one partial skeleton, 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...
USNM 2364, which includes an ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
, a 76 centimetres long humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
, a scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
, a partial radius
Radius
In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...
, and some metacarpals discovered in August 1859 by John Strong Newberry
John Strong Newberry
John Strong Newberry was a American geologist, physician, explorer, author, and a member of the Megatherium Club at the Smithsonian Institution in Washington, D.C....
. It was found in what is possibly stratigraphic zone 1 of the Morrison, although an older Oxfordian-Callovian
Callovian
In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....
has also been suggested. Dystropheus represents one of the oldest discoveries of sauropods in America; earlier, in 1855, some teeth had been found of Astrodon
Astrodon
Astrodon was a genus of large herbivorous sauropod dinosaur, related to Brachiosaurus, that lived in what is now the eastern United States during the Early Cretaceous period. Its fossils have been found in the Arundel Formation, which has been dated through palynomorphs to the Aptian-Albian...
.
The classification of Dystrophaeus has been rather confusing. Cope in 1877 merely concluded it was some Triassic dinosaur. Henri-Émile Sauvage in 1882 understood it was a sauropod, assigning it to the Atlantosauridae. Othniel Charles 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...
however, in 1895 stated it belonged to the Stegosauridae
Stegosauridae
Stegosauridae is a family of stegosauria, large thyreophorans. They lived longer than other Stegosaurs; while all Huayangosauridae and most of basal stegosaurs died out in Tithonian - Kimmeridgian, stegosauridae survived till Middle Cretaceous. They are usually characterized by triangular plates on...
. Friedrich von Huene
Friedrich von Huene
Friedrich von Huene was a German paleontologist who named more dinosaurs in the early 20th century than anyone else in Europe.-Biography:...
, the first to determine it was of Jurassic age, in 1904 created a special family for it, the Dystrophaeidae, which he assumed to be herbivorous theropods. Only in 1908 von Huene realised his mistake and classified it in the sauropod Cetiosauridae, refining this in 1927 to the Cardiodontinae. Alfred Romer
Alfred Romer
Alfred Sherwood Romer was an American paleontologist and comparative anatomist and a specialist in vertebrate evolution.-Biography:...
in 1966 put it in the Brachiosauridae
Brachiosauridae
Brachiosauridae are a family of dinosaurs, whose members are known as brachiosaurids. They were herbivorous quadrupeds with longer forelegs than hind legs - the name derives from the Greek for arm lizard - and long necks...
, in a subfamily Cetiosaurinae.
Finally, a modern analysis by David Gillette
David Gillette
David Gillette is an American paleontologist best known for his discovery of the dinosaur Diplodocus hallorum. At the time of its discovery, Diplodocus was the longest dinosaur known.-Gillette's Diplodocus hallorum discovery:...
concluded it was a member of the Diplodocidae. However, many researchers consider the taxon to be a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
.