Grallator
Encyclopedia
Grallator is an ichnogenus (form taxon based on footprints) which covers a common type of small, three-toed print made by a variety of bipedal theropod dinosaur
s. Grallator-type footprints have been found in formations dating from the late Triassic
through to the early Cretaceous
periods. They are found in the United States
, Canada
, Europe
, Australia
and China
but are most abundant on the east coast of North America, especially the Triassic
and Early Jurassic
formations of the northern part of the Newark Supergroup
. The name Grallator translates into "stilt walker", although the actual length and form of the trackmaking legs varied by species, usually unidentified. The related term "Grallae" is an ancient name for the presumed group of long-legged wading birds, such as stork
s and heron
s. These footprints were given this name by their discover, Edward Hitchcock
, in 1858.
Grallator footprints are characteristically three-toed (tridactyl) and range from 5 to 15 centimeters (or 2 to 6 inches) long. Though the tracks show only three toes, the trackmakers likely had between four five toes on their feet. While it is usually impossible to match these prints with the exact dinosaur species that left them, it is sometimes possible to narrow down potential trackmakers by comparing the proportions in individual Grallator ichnospecies with known dinosaurs of the same formation. For example, Grallator tracks identified from the Yixian Formation
may have been left by Caudipteryx
.
. The Newark Supergroup footprints show digits II, III and IV, but no trace of the shorter digits I and V which would likely have been present in a dinosaur of this stage. The outer two digits would have been stubby and ineffective, not touching the ground during walking or running. Despite losing most of their effectiveness, dinosaur evolution had not yet removed the these digits to fully streamline the foot. This is known because rare specimens are found with traces of these outer digits. Digits II, III and IV have 3, 4 and 5 phalanges respectively, giving Grallator a ?-3-4-5-? digital formula.
Although the Newark Supergroup Grallator tracks were made by a bipedal saurischian dinosaur, they can easily be mistaken for those of the late Triassic ichnogenus Atreipus
. The trackmaker of Atreipus prints was a quadrupedal ornithischian. The reason for this similarity is a lack of divergence in the foot evolution of the two distinct groups of dinosaurs: ornithischians and saurischians.
Period. This footprint type was first identified by S. Zhen et al. in China
, in 1989. Its type ichnospecies is J. yuechiensis, with the genus being named after the Jialing River
in Sichuan
.
All known synonyms:
stratum
dating to the Norian
in southern Wales
preserves tracks of an individual with a deformed digit III attribute to the ichnogenus Anchisauripus. The distal end of the digit was consistently flexed. However, this apparent pathology could be caused by the animal rotating the tip of that digit when lifting the foot.
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...
s. Grallator-type footprints have been found in formations dating from the late Triassic
Late Triassic
The Late Triassic is in the geologic timescale the third and final of three epochs of the Triassic period. The corresponding series is known as the Upper Triassic. In the past it was sometimes called the Keuper, after a German lithostratigraphic group that has a roughly corresponding age...
through to the early Cretaceous
Early Cretaceous
The Early Cretaceous or the Lower Cretaceous , is the earlier or lower of the two major divisions of the Cretaceous...
periods. They are found in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
but are most abundant on the east coast of North America, especially the Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
and Early Jurassic
Early Jurassic
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...
formations of the northern part of the Newark Supergroup
Newark Group
The Newark Group, also known as the Newark Supergroup, is an assemblage of Late Triassic and Early Jurassic sedimentary rocks which outcrop intermittently along the United States East Coast; the exposures extend from Massachusetts to North Carolina, with more still in Nova Scotia...
. The name Grallator translates into "stilt walker", although the actual length and form of the trackmaking legs varied by species, usually unidentified. The related term "Grallae" is an ancient name for the presumed group of long-legged wading birds, such as stork
Stork
Storks are large, long-legged, long-necked wading birds with long, stout bills. They belong to the family Ciconiidae. They are the only family in the biological order Ciconiiformes, which was once much larger and held a number of families....
s and heron
Heron
The herons are long-legged freshwater and coastal birds in the family Ardeidae. There are 64 recognised species in this family. Some are called "egrets" or "bitterns" instead of "heron"....
s. These footprints were given this name by their discover, Edward Hitchcock
Edward Hitchcock
Edward Hitchcock was a noted American geologist and the third President of Amherst College .-Life:...
, in 1858.
Grallator footprints are characteristically three-toed (tridactyl) and range from 5 to 15 centimeters (or 2 to 6 inches) long. Though the tracks show only three toes, the trackmakers likely had between four five toes on their feet. While it is usually impossible to match these prints with the exact dinosaur species that left them, it is sometimes possible to narrow down potential trackmakers by comparing the proportions in individual Grallator ichnospecies with known dinosaurs of the same formation. For example, Grallator tracks identified from the Yixian Formation
Yixian Formation
The Yixian Formation is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans 11 million years during the early Cretaceous period...
may have been left by Caudipteryx
Caudipteryx
Caudipteryx is a genus of peacock-sized theropod dinosaurs that lived in the Aptian age of the early Cretaceous Period . They were feathered and remarkably birdlike in their overall appearance....
.
Newark Supergroup tracks
The most famous, and archetypal tracks that conform to the Grallator type are those found on the East Coast of North America, specifically from the Late Triassic to Early Jurassic Newark Supergroup. These footprints were likely made by an unidentified, primitive dinosaur similar to CoelophysisCoelophysis
Coelophysis , meaning "hollow form" in reference to its hollow bones , is one of the earliest known genera of dinosaur...
. The Newark Supergroup footprints show digits II, III and IV, but no trace of the shorter digits I and V which would likely have been present in a dinosaur of this stage. The outer two digits would have been stubby and ineffective, not touching the ground during walking or running. Despite losing most of their effectiveness, dinosaur evolution had not yet removed the these digits to fully streamline the foot. This is known because rare specimens are found with traces of these outer digits. Digits II, III and IV have 3, 4 and 5 phalanges respectively, giving Grallator a ?-3-4-5-? digital formula.
Although the Newark Supergroup Grallator tracks were made by a bipedal saurischian dinosaur, they can easily be mistaken for those of the late Triassic ichnogenus Atreipus
Atreipus
Atreipus is an ichnogenus of trace fossil attributed to theropod dinosaurs....
. The trackmaker of Atreipus prints was a quadrupedal ornithischian. The reason for this similarity is a lack of divergence in the foot evolution of the two distinct groups of dinosaurs: ornithischians and saurischians.
Synonyms
Jialingpus is a synonymous ichnogenus that covers a type of small, three-toed print made by an unidentified species of bipedal theropod dinosaur. Jialingpus-type footprints have been found in formations dating from the JurassicJurassic
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...
Period. This footprint type was first identified by S. Zhen et al. in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, in 1989. Its type ichnospecies is J. yuechiensis, with the genus being named after the Jialing River
Jialing River
The Jialing River is a tributary of the Yangtze River with its source in Gansu province. It gets its name from its crossing the Jialing Vale in Feng County of Shaanxi. It was once known as Langshui or Yushui .-Overview:...
in Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...
.
All known synonyms:
- Abelichnus
- Aetonychops
- Apatichnus
- Bressanichnus
- Byakudansauripus
- Columbosauripus
- Changpeipus
- Coelurosaurichnus Huene, 1941
- Defferrariichium
- Dilophosauripus
- Dinosaurichnium
- Eubrontes
- Gigantipus
- Hyphepus
- Irenesauripus
- Itsukisauropus
- Jeholosauripus Yabe, Inai, & Shikama, 1940
- Jialingpus
- Kainotrisauropous
- Kayentapus
- Kleitotrisauropus
- Komlosaurus
- Kuwajimasauropus
- Masitisauropus
- Megalosauropus
- Megatrisauropus
- Neotrisauropus
- Otouphepus
- Paracoelurosaurichnus
- Picunichnus
- Plastisauropus
- Platytrisauropus
- Prototrisauropus
- Qemetrisauropus
- Saltopoides
- "Sauropous"
- Schizograllator
- Skartopus
- Stenonyx
- Talmontopus
- Youngichnus
- Zhengichnus
Species
- Subgenus G. (Coelurosaurichnus)
- G. (C.) palmipes
- G. (C.) p. exiguus (Ellenberger, 1970)
- G. (C.) palmipes
- Subgenus G. (Grallator)
- G. (G.) zvierzi Gierlinski, 1991
- G. andeolensis Gand, Vianey-Liaud, Demathieu, & Garric, 2000
- G. angustidigitus (Ellenberger, 1970)
- G. angustus (Ellenberger, 1974)
- G. a. cursor Ellenberger, 1974
- G. cursorius HitchcockEdward HitchcockEdward Hitchcock was a noted American geologist and the third President of Amherst College .-Life:...
, 1858 (ichnotypeType speciesIn 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...
) - G. cuneatus HitchcockEdward HitchcockEdward Hitchcock was a noted American geologist and the third President of Amherst College .-Life:...
, 1858 - G. damanei Ellenberger, 1970
- G. deambulator (Ellenberger, 1970)
- G. digitigradus (Ellenberger, 1974)
- G. emeiensis Zhen, Li, Han & Yang, 1995
- G. formosus HitchcockEdward HitchcockEdward Hitchcock was a noted American geologist and the third President of Amherst College .-Life:...
, 1858 - G. gracilis Hitchcock, 1865
- G. graciosus (Ellenberger, 1970)
- G. grancier (CourelCourelCourel is a Portuguese parish, located in the municipality of Barcelos. It has a population of 518 inhabitants and a total area of 5.46 km²....
& Demathieu, 2000) - G. ingens (Ellenberger, 1970)
- G. kehli (Beurlen, 1950)
- G. kronbergeri (Rehnelt, 1959)
- G. lacunensis (Ellenberger, 1970)
- G. leribeensis (Ellenberger, 1970)
- G. limnosus Zhen, Li, & Rao, 1985
- G. madseni Irby, 1995
- G. magnificus (Ellenberger, 1970)
- G. matsiengensis Ellenberger, 1970
- G. maximus Lapparent & Monetnat, 1967
- G. minimus (Ellenberger, 1970)
- G. minor (Ellenberger, 1970)
- G. moeni (Beurlen, 1950)
- G. mokanametsongensis (Ellenberger, 1974)
- G. molapoi Ellenberger, 1974
- G. morijiensis (Ellenberger, 1970)
- G. moshoeshoei (Ellenberger, 1970)
- G. olonensis Lapparent & Monetnat, 1967
- G. palissyi (Gand, 1976)
- G. paulstris (Ellenberger, 1970)
- G. perriauxi (Demathieu & GrandGrand (surname)Grand* Cedric Grand , Swiss bobsledder* Gil Grand , Canadian country music singer* Jean-Pierre Grand , French politician* Pascale Grand , Canadian racewalker* Sarah Grand , British feminist writer...
, 1972) - G. princeps (Ellenberger, 1970)
- G. protocrassidigitus (Ellenberger, 1970)
- G. rapidus (Ellenberger, 1974)
- G. romanovskyi (Gabunia & Kurbatov)
- G. quthingensis (Ellenberger, 1974)
- G. rectilineus (Ellenberger, 1970)
- G. sabinensis (Gand & Pellier, 1976)
- G. sassendorfensis (Kuhn, 1958)
- G. sauclierensis Demathieu & Sciau, 1992
- G. schlauersbachensis (Weiss, 1934)
- G. socialis (Ellenberger, 1970)
- G. ssatoi Yabe, Inai, & Shikama, 1940
- G. tenuis HitchcockEdward HitchcockEdward Hitchcock was a noted American geologist and the third President of Amherst College .-Life:...
, 1858 - G. toscanus (Huene, 1941)
- G. variabilis Lapparent & Monetnat, 1967
Paleopathology
Fossil tracks can be informative about theropod pathologies but apparently pathological traits may be due to unusual behaviors. SandstoneSandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
stratum
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
dating to the Norian
Norian
The Norian is a division of the Triassic geological period. It has the rank of an age or stage . The Norian lasted from 216.5 ± 2.0 to 203.6 ± 1.5 million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.-Stratigraphic definitions:The Norian was named after the Noric Alps in...
in southern Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
preserves tracks of an individual with a deformed digit III attribute to the ichnogenus Anchisauripus. The distal end of the digit was consistently flexed. However, this apparent pathology could be caused by the animal rotating the tip of that digit when lifting the foot.