''Gryposaurus'' (meaning "hooked-nosed (
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
''grypos'')
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
";
sometimes incorrectly translated as "
griffin
The griffin, griffon, or gryphon (Ancient Greek: , ''gryps''; Classical Latin: ''grȳps'' or ''grȳpus''; Late Latin, Late and Medieval Latin: ''gryphes'', ''grypho'' etc.; Old French: ''griffon'') is a legendary creature with the body, tail ...
(
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''gryphus'') lizard"
) was a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
duckbilled dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
that lived about 80 to 75 million years ago, in the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
(late
Santonian
The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...
to late
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...
stages
Stage or stages may refer to:
Acting
* Stage (theatre), a space for the performance of theatrical productions
* Theatre, a branch of the performing arts, often referred to as "the stage"
* ''The Stage'', a weekly British theatre newspaper
* S ...
) of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
. Named species of ''Gryposaurus'' are known from the
Dinosaur Park Formation
The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76. ...
in
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
, Canada, and two formations in the United States: the Lower
Two Medicine Formation
The Two Medicine Formation is a geological formation, or rock body, in northwestern Montana and southern Alberta that was deposited between and (million years ago), during Campanian (Late Cretaceous) time. It crops out to the east of the Rocky M ...
in
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...
and the
Kaiparowits Formation
The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase–Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet (850 m) thick, and is Ca ...
of
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
. A possible additional species from the
Javelina Formation in Texas may extend the temporal range of the genus to 66 million years ago.
''Gryposaurus'' is similar to ''
Kritosaurus
''Kritosaurus'' is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek ...
'', and for many years the two were thought to be synonyms. It is known from numerous skulls, some skeletons, and even some skin impressions that show it to have had pyramidal scales projecting along the midline of the back. It is most easily distinguished from other duckbills by its narrow arching nasal hump, sometimes described as similar to a "
Roman nose
Roman Nose ( – September 17, 1868), also known as Hook Nose ( chy, Vóhko'xénéhe, also spelled Woqini and Woquini), was a Native Americans in the United States, Native American of the Northern Cheyenne. He is considered to be one of, if not ...
,"
[ and which may have been used for species or sexual identification, and/or combat with individuals of the same species. A large ]bipedal
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...
/quadrupedal
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...
herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
around long, it may have preferred river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
settings.
History of discovery
''Gryposaurus'' is based on specimen NMC 2278, a skull and partial skeleton collected in 1913 by George F. Sternberg from what is now known as the Dinosaur Park Formation
The Dinosaur Park Formation is the uppermost member of the Belly River Group (also known as the Judith River Group), a major geologic unit in southern Alberta. It was deposited during the Campanian stage of the Late Cretaceous, between about 76. ...
of Alberta, along the Red Deer River
The Red Deer River is a river in Alberta and a small portion of Saskatchewan, Canada. It is a major tributary of the South Saskatchewan River and is part of the larger Saskatchewan-Nelson system that empties into Hudson Bay.
Red Deer River ...
.[ This specimen was described and named by ]Lawrence Lambe
Lawrence Morris Lambe (August 27, 1863 – March 12, 1919) was a Canadian geologist, palaeontologist, and ecologist from the Geological Survey of Canada (GSC).
His published work, describing the diverse and plentiful dinosaur discoveries from th ...
shortly thereafter, Lambe drawing attention to its unusual nasal crest.[ A few years earlier, ]Barnum Brown
Barnum Brown (February 12, 1873 – February 5, 1963), commonly referred to as Mr. Bones, was an American paleontologist. Named after the circus showman P. T. Barnum, he discovered the first documented remains of ''Tyrannosaurus'' during a career ...
had collected and described a partial skull from New Mexico, which he named ''Kritosaurus
''Kritosaurus'' is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek ...
''. This skull was missing the snout, which had eroded into fragments; Brown restored it after the duckbill now known as ''Edmontosaurus annectens
''Edmontosaurus annectens'' (meaning "connected lizard from Edmonton") is a species of flat-headed and duck-billed (hadrosaurid) dinosaur from the very end of the Cretaceous Period (geology), Period, in what is now North America. Remains of ''E. ...
'', which was flat-headed, and believed that some unusual pieces were evidence of compression.[ Lambe's description of ''Gryposaurus'' provided evidence of a different type of skull configuration, and by 1916 the ''Kritosaurus'' skull had been redone with a nasal arch and both Brown and Charles Gilmore had proposed that ''Gryposaurus'' and ''Kritosaurus'' were one and the same.] This idea was reflected in William Parks's naming of a nearly complete skeleton from the Dinosaur Park Formation as ''Kritosaurus incurvimanus'', not ''Gryposaurus incurvimanus'' (although he left ''Gryposaurus notabilis'' in its own genus). Direct comparison between ''Kritosaurus incurvimanus'' and ''Gryposaurus notabilis'' is hindered by the fact that the ''incurvimanus'' type specimen is missing the front part of the skull, so the full shape of the nasal arch cannot be seen. The 1942 publication of the influential Lull and Wright monograph
A monograph is a specialist work of writing (in contrast to reference works) or exhibition on a single subject or an aspect of a subject, often by a single author or artist, and usually on a scholarly subject.
In library cataloging, ''monograph ...
on hadrosaurs sealed the ''Kritosaurus''/''Gryposaurus'' question for nearly fifty years in favor of ''Kritosaurus''. Reviews beginning in the 1990s, however, called into question the identity of ''Kritosaurus navajovius'', which has limited material for comparison with other duckbills.[ Thus, ''Gryposaurus'' has once again been separated, at least temporarily, from ''Kritosaurus''.
]
This situation is made more confusing by old suggestions by some authors, including Jack Horner, that ''Hadrosaurus
''Hadrosaurus'' (; ) is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 80 million to 78 million years ago. The holotype specimen was found in f ...
'' is also the same as either ''Gryposaurus'', ''Kritosaurus'', or both. This hypothesis
A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obse ...
was most common in the late 1970s–early 1980s, and appears in some popular books; one well-known work, ''The Illustrated Encyclopedia of Dinosaurs'', uses ''Kritosaurus'' for the Canadian material (''Gryposaurus''), but identifies the mounted skeleton of ''K. incurvimanus'' as ''Hadrosaurus'' in a photo caption. Although Horner in 1979 used the new combination ''Hadrosaurus ritosaurusnotabilis'' for a partial skull and skeleton and a second less-complete skeleton from the Bearpaw Shale
The Bearpaw Formation, also called the Bearpaw Shale, is a geologic formation of Late Cretaceous (Campanian) age. It outcrops in the U.S. state of Montana, as well as the Canadian provinces of Alberta and Saskatchewan, and was named for the Bear ...
of Montana[ (which have since fallen out of the literature), by 1990 he had changed his position, and was among the first to again use ''Gryposaurus'' in print.][ Current thought is that ''Hadrosaurus'', although known from fragmentary material, can be distinguished from ''Gryposaurus'' by differences in the ]upper arm
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...
and ilium.
Further research has revealed the presence of a second species, ''G. latidens'', from slightly older rocks in Montana than the classic gryposaur localities of Alberta. Based on two parts of a skeleton collected in 1916 for the American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
, ''G. latidens'' is also known from bonebed
A bone bed is any geological stratum or deposit that contains bones of whatever kind. Inevitably, such deposits are sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätt ...
material. Horner, who described the specimens, considered it to be a less derived
Derive may refer to:
* Derive (computer algebra system), a commercial system made by Texas Instruments
* ''Dérive'' (magazine), an Austrian science magazine on urbanism
*Dérive, a psychogeographical concept
See also
*
*Derivation (disambiguatio ...
species.[
New material from the ]Kaiparowits Formation
The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase–Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet (850 m) thick, and is Ca ...
of Utah, in Grand Staircase–Escalante National Monument
The Grand Staircase–Escalante National Monument (GSENM) is a United States national monument protecting the Grand Staircase, the Kaiparowits Plateau, and the Canyons of the Escalante (Escalante River) in southern Utah. It was established in 199 ...
, includes a skull and partial skeleton that represent the species ''G. monumentensis''. Its skull was more robust than that of the other species, and its predentary
Ornithischia () is an extinct order of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name ''Ornithischia'', or "bird-hipped", reflects this similarity and is derived from the Greek st ...
had enlarged prongs along its upper margin, where the lower jaw's beak was based. This new species greatly expands the geographic range of this genus, and there may be a second, more lightly built species present as well. Multiple gryposaur species are known from the Kaiparowits Formation, represented by cranial and postcranial remains, and were larger than their northern counterparts.
In Texas, specifically at the Javelina Formation and the El Picacho Formation, indeterminate hadrosaur remains resembling ''Kritosaurus'' and ''Gryposaurus'' have been unearthed for decades, but none were considered to be identifiable as a determined genus of hadrosaur, but do resemble some species of Kritosaurini
Kritosaurini is a tribe of saurolophine hadrosaurid dinosaurs from the Late Cretaceous.
Discovery and naming
The first member of the group discovered and named was ''Kritosaurus''; it was named by paleontologist Barnum Brown in 1910. Four year ...
or at least some species of ''Kritosaurus
''Kritosaurus'' is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek ...
''. However, in 2016, a possibly forth valid species of ''Gryposaurus'' named ''G. alsatei'', which was named after Alsate Alsate, also known as Arzate, Arzatti, and Pedro Múzquiz, (ca. 1820 – 1881/1882) was the last chief of the Chisos band of Limpia Mescalero Apaches.
He was the son of Josè Miguel Maria del Refugio Sabas Muzquiz Gonzalez, who was captured by ...
, who was the last leader of the Mescalero
Mescalero or Mescalero Apache ( apm, Naa'dahéńdé) is an Apache tribe of Southern Athabaskan–speaking Native Americans. The tribe is federally recognized as the Mescalero Apache Tribe of the Mescalero Apache Reservation, located in south-cen ...
Apache
The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño an ...
s, was unearthed in the Javelina Formation in Texas. Further research is needed to confirm its validity.
Species
As of 2016, there are currently three named species that are recognized as valid today: ''G. notabilis'', ''G. latidens'', and ''G. monumentensis''. The type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
''G. notabilis'' is from the late Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian ...
-age Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
Dinosaur Park Formation of Alberta, Canada.[ It is now thought that another species from the same formation, ''Kritosaurus incurvimanus'' (also known as ''Gryposaurus incurvimanus''), is a synonym of ''G. notabilis''.][ The two had been differentiated by the size of the nasal arch (larger and closer to the eyes in ''G. notabilis'') and the form of the upper arm (longer and more robust in ''K. incurvimanus'').][ Ten complete skulls and twelve fragmentary skulls are known for ''G. notabilis'' along with ]postcrania Postcrania (postcranium, adjective: postcranial) in zoology and vertebrate paleontology is all or part of the skeleton apart from the skull. Frequently, fossil remains, e.g. of dinosaurs or other extinct tetrapods, consist of partial or isolated sk ...
,[ as well as with two skeletons with skulls that had been assigned to ''K. incurvimanus''.] ''G. latidens'', from the late Santonian-early Campanian Lower Two Medicine Formation of Pondera County, Montana, USA, is known from partial skulls and skeletons from several individuals. Its nasal arch is prominent like that of ''G. notabilis'', but farther forward on the snout, and its teeth are less derived
Derive may refer to:
* Derive (computer algebra system), a commercial system made by Texas Instruments
* ''Dérive'' (magazine), an Austrian science magazine on urbanism
*Dérive, a psychogeographical concept
See also
*
*Derivation (disambiguatio ...
, reflecting iguanodont
Iguanodontia (the iguanodonts) is a clade of herbivorous dinosaurs that lived from the Middle Jurassic to Late Cretaceous. Some members include ''Camptosaurus'', ''Dryosaurus'', ''Iguanodon'', '' Tenontosaurus'', and the hadrosaurids or "duck-bil ...
-like characteristics.[ The informal name "Hadrosauravus"] is an early, unused name for this species. ''G. monumentensis'' is known from a skull and partial skeleton from Utah.[ ''G. monumentensis'' was listed second on the top 10 list of new species in 2008 by the ]International Institute for Species Exploration
The International Institute for Species Exploration (IISE) is a research institute located in Syracuse, New York. Its mission is to improve taxonomical exploration and the cataloging of new species of flora and fauna. Since 2008, IISE has publ ...
. Recently, a possible fourth species of ''Gryposaurus'', ''Gryposaurus alsatei'', was unearthed in the Javelina Formation, which dates to the late Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...
, along with an unnamed species of ''Kritosaurus'' and an undescribed saurolophine
Saurolophinae is a subfamily (biology), subfamily of hadrosaurid dinosaurs. It has since the mid-20th century generally been called the Hadrosaurinae, a group of largely non-crested hadrosaurs related to the crested sub-family Lambeosaurinae. How ...
which closely resembles ''Saurolophus
''Saurolophus'' (; meaning "lizard crest") is a genus of large hadrosaurid dinosaur from the Late Cretaceous period of Asia and North America, that lived in what is now the Horseshoe Canyon and Nemegt formations about 70 million to 68 million ...
'', but with a more solid crest.
The dubious hadrosaurid ''Stephanosaurus marginatus'' was considered a possible species of ''Kritosaurus'', following the synonymy of ''Gryposaurus'' with ''Kritosaurus''.[ However, this synonymy was rejected in the 2004 edition of the ''Dinosauria'', with ''Stephanosaurus'' being tabulated as dubious.][
]
Description
''Gryposaurus'' was a hadrosaurid of typical size and shape; one of the best specimens of this genus, the nearly complete type specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...
of ''Kritosaurus incurvimanus'' (now regarded as a synonym of ''Gryposaurus notabilis'') came from an animal about long. This specimen also has the best example of skin
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation.
Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
impressions for ''Gryposaurus'', showing this dinosaur to have had several different types of scalation: pyramidal, ridged, limpet
Limpets are a group of aquatic snails that exhibit a conical shell shape (patelliform) and a strong, muscular foot. Limpets are members of the class Gastropoda, but are polyphyletic, meaning the various groups called "limpets" descended indep ...
-shaped scutes upwards of 3.8 centimeters long (1.5 inches) on the flank and tail; uniform polygonal scales on the neck and sides of the body; and pyramidal structures, flattened side-to-side, with fluted sides, longer than tall and found along the top of the back in a single midline row. In 2016, Gregory S. Paul estimated the size of ''G. latidens'' at in length and in body mass and the other two species (''G. notabilis'' and ''G. monumentensis'') at in length and in body mass.
The three named species of ''Gryposaurus'' differ in details of the skull and lower jaw.[ The prominent nasal arch found in this genus is formed from the paired ]nasal bone
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose.
Eac ...
s. In profile view, they rise into a rounded hump in front of the eyes, reaching a height as tall as the highest point of the back of the skull. The skeleton is known in great detail, making it a useful point of reference for other duckbill skeletons.
Classification
''Gryposaurus'' was a saurolophine (hadrosaurine of older references) hadrosaurid, a member of the duckbill subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
without hollow head crests. The general term "gryposaur" is sometimes used for duckbills with arched nasals. ''Tethyshadros
''Tethyshadros'' ("Tethys Ocean, Tethyan hadrosauroid") is a genus of hadrosauroidea, hadrosauroid dinosaur from Trieste, Italy. The type and only species is ''T. insularis''.
Discovery and naming
Sometime in the 1980s, Alceo Tarlao and Giorgi ...
'' was once thought to fall into this group as well, before it was described (then known under the nickname "Antonio"). A subfamily, Gryposaurinae, was coined by Jack Horner as part of a larger revision that promoted Hadrosaurinae to family status, but is not now in use. A rough equivalent is Kritosaurini
Kritosaurini is a tribe of saurolophine hadrosaurid dinosaurs from the Late Cretaceous.
Discovery and naming
The first member of the group discovered and named was ''Kritosaurus''; it was named by paleontologist Barnum Brown in 1910. Four year ...
, as used by Alberto Prieto-Márquez. ''Kritosaurus
''Kritosaurus'' is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek ...
'' has been proposed to be a synonym of ''Gryposaurus'', but it is slightly younger. Additionally, while the skull of ''Kritosaurus'' is incompletely known, lacking most of the bones in front of the eyes, it was very similar to that of ''Gryposaurus''.
The following is a cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
based on the phylogenetic analysis conducted by Prieto-Márquez and Wagner in 2012, showing the relationships of ''Gryposaurus'' among the other kritosaurins:[
]
Paleobiology
As a hadrosaurid
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which inclu ...
, ''Gryposaurus'' would have been a bipedal
Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...
/quadruped
Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...
al herbivore
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
, eating a variety of plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
s. Its skull had special joints that permitted a grinding motion analogous to chewing
Chewing or mastication is the process by which food is crushed and ground by teeth. It is the first step of digestion, and it increases the surface area of foods to allow a more efficient break down by enzymes. During the mastication process, th ...
, and its teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...
were continually replacing and packed into dental batteries
Dinosaur teeth have been studied since 1822 when Mary Ann Mantell (1795-1869) and her husband Dr Gideon Algernon Mantell (1790-1852) discovered an ''Iguanodon'' tooth in Sussex in England. Unlike mammal teeth, individual dinosaur teeth are gener ...
that contained hundreds of teeth, only a relative handful of which were in use at any time. Plant material would have been cropped by its broad beak, and held in the jaws by a cheek
The cheeks ( la, buccae) constitute the area of the face below the eyes and between the nose and the left or right ear. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside ...
-like organ. Its feeding range would have extended from the ground to about above.[ The paleontologists who unearthed ''G.'' ''monumentensis'' back in the 2000s brought the fact that this creature dined on tough, fibrous plant material which would imply that ''Gryposaurs'' was both a ]grazer Grazer may refer to:
*grazer, an animal that grazes
*Grazer, a native or inhabitant of Graz
*GRAZER, the shoegaze band GRAZER
Astronomy
*Earth Grazer, Earth-grazing fireball that enters the Earth's atmosphere and leaves again
*Mercury grazer, ast ...
and a browser.
Like other bird-hipped dinosaurs of the Dinosaur Park Formation, ''Gryposaurus'' appears to have only existed for part of the duration of time that the rocks were being formed. As the formation was being laid down, it recorded a change to more marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
* Marine habitats
* Marine life
* Marine pollution
Military
* ...
-influenced conditions. ''Gryposaurus'' is absent from the upper part of the formation, with ''Prosaurolophus
''Prosaurolophus'' (; meaning "before ''Saurolophus''", in comparison to the later dinosaur with a similar head crest) is a genus of hadrosaurid (or duck-billed) dinosaur from the Late Cretaceous of North America. It is known from the remains of ...
'' present instead. Other dinosaurs known from only the lower part of the formation include the horned ''Centrosaurus
''Centrosaurus'' ( ; ) is a genus of herbivorous ceratopsian dinosaur from the Late Cretaceous of Canada. Their remains have been found in the Dinosaur Park Formation, dating from 76.5 to 75.5 million years ago.
Discovery and naming
The firs ...
'' and the hollow-crested duckbill ''Corythosaurus
''Corythosaurus'' (; ) is a genus of hadrosaurid "duck-billed" dinosaur from the Upper Cretaceous Period (geology), Period, about 77–75.7 million years ago. It lived in what is now North America. Its name means "helmet lizard", derived fr ...
''.[ ''Gryposaurus'' may have preferred ]river
A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...
-related settings.[
]
Nasal arch
The distinctive nasal arch of ''Gryposaurus'', like other cranial modifications in duckbills, may have been used for a variety of social functions, such as identification of sexes or species and social ranking.[ It could also have functioned as a tool for broadside pushing or butting in social contests, and there may have been inflatable air sacs flanking it for both visual and auditory signaling.] The top of the arch is roughened in some specimens, suggesting that it was covered by thick, keratin
Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. Alpha-keratin (α-keratin) is a type of keratin found in vertebrates. It is the key structural material making up scales, hair, nails, feathers, ho ...
ized skin,[ or that there was a ]cartilaginous
Cartilage is a resilient and smooth type of connective tissue. In tetrapods, it covers and protects the ends of long bones at the joints as articular cartilage, and is a structural component of many body parts including the rib cage, the neck and ...
extension.[
]
Paleoecology
Utah
Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
period. During the Late Cretaceous period, the site of the Kaiparowits Formation was located near the western shore of the Western Interior Seaway
The Western Interior Seaway (also called the Cretaceous Seaway, the Niobraran Sea, the North American Inland Sea, and the Western Interior Sea) was a large inland sea that split the continent of North America into two landmasses. The ancient sea, ...
, a large inland sea that split North America into two landmasses, Laramidia
Laramidia was an island continent that existed during the Late Cretaceous period (99.6–66 Ma), when the Western Interior Seaway split the continent of North America in two. In the Mesozoic era, Laramidia was an island land mass separated from A ...
to the west and Appalachia
Appalachia () is a cultural region in the Eastern United States that stretches from the Southern Tier of New York State to northern Alabama and Georgia. While the Appalachian Mountains stretch from Belle Isle in Newfoundland and Labrador, Ca ...
to the east. The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and abundant wetland peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...
swamps, ponds and lakes, and was bordered by highlands. The climate was wet and humid, and supported an abundant and diverse range of organisms. This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.
''Gryposaurus monumentensis'' shared its paleoenvironment
Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...
with other dinosaurs, such as dromaeosaurid
Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning ...
theropod
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...
s, the troodontid
Troodontidae is a clade of bird-like theropod dinosaurs. During most of the 20th century, troodontid fossils were few and incomplete and they have therefore been allied, at various times, with many dinosaurian lineages. More recent fossil discov ...
''Talos sampsoni
''Talos'' is an extinct genus of carnivorous bird-like theropod dinosaur, an advanced troodontid which lived during the late Cretaceous period (late Campanian, about 76 Ma) in the geographic area that is now Utah, United States.
Discovery
'' ...
'', ornithomimids
Ornithomimidae (meaning "bird-mimics") is a family of theropod dinosaurs which bore a superficial resemblance to modern ostriches. Ornithomimids were fast, omnivorous or herbivorous dinosaurs known mainly from the Late Cretaceous Period of Lauras ...
like ''Ornithomimus velox
''Ornithomimus'' (; "bird mimic") is a genus of ornithomimid dinosaurs from the Late Cretaceous Period of what is now North America. ''Ornithomimus'' was a swift bipedal theropod which fossil evidence indicates was covered in feathers, equipped ...
'', tyrannosaurids
Tyrannosauridae (or tyrannosaurids, meaning "tyrant lizards") is a family (biology), family of coelurosaurian Theropoda, theropod dinosaurs that comprises two subfamilies containing up to thirteen genus, genera, including the eponymous ''Tyrannos ...
like ''Albertosaurus
''Albertosaurus'' (; meaning "Alberta lizard") is a genus of tyrannosaurid theropod dinosaurs that lived in western North America during the Late Cretaceous Period, about 71 million years ago. The type species, ''A. sarcophagus'', was app ...
'' and ''Teratophoneus
''Teratophoneus'' ("monstrous murderer"; Greek: ''teras'', "monster" and ''phoneus'', "murderer") is a genus of tyrannosaurid dinosaur which lived during the late Cretaceous period (late Campanian age, about 77 to 76 million years ago) in what i ...
'', armored ankylosaurids, the duckbilled hadrosaur ''Parasaurolophus cyrtocristatus
''Parasaurolophus'' (; meaning "near crested lizard" in reference to '' Saurolophus)'' is a genus of herbivorous hadrosaurid ornithopod dinosaur that lived in what is now North America and possibly Asia during the Late Cretaceous Period, ab ...
'', the ceratopsians
Ceratopsia or Ceratopia ( or ; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. ...
''Utahceratops gettyi
''Utahceratops'' is an extinct genus of ceratopsian dinosaur that lived approximately 76.4~75.5 million years ago during the Late Cretaceous period in what is now Utah. ''Utahceratops'' was a large-sized, robustly-built, ground-dwelling, quadrupe ...
'', ''Nasutoceratops titusi
''Nasutoceratops'' is an extinct genus of ceratopsian dinosaur. It is a basal Centrosaurinae, centrosaurine which lived during the Late Cretaceous period (geology), Period (late Campanian, about 76.0-75.5 Mya (unit), Ma). Fossils have been found ...
'' and ''Kosmoceratops richardsoni
''Kosmoceratops'' () is a genus of ceratopsid dinosaur that lived in North America about 76–75.9 million years ago during the Late Cretaceous period. Specimens were discovered in Utah in the Kaiparowits Formation of the Grand Staircase–Esca ...
'' and the oviraptorosauria
Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or wit ...
n ''Hagryphus giganteus
''Hagryphus'' (meaning " Ha's griffin") is a monospecific genus of caenagnathid dinosaur from southern Utah that lived during the Late Cretaceous (upper Campanian stage, 75.95 Ma) in what is now the Kaiparowits Formation of the Grand Staircase– ...
''. Other paleofauna present in the Kaiparowits Formation included chondrichthyans
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. C ...
(sharks and rays), frog
A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...
s, salamander
Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...
s, turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...
s, lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...
s and crocodilia
Crocodilia (or Crocodylia, both ) is an order of mostly large, predatory, semiaquatic reptiles, known as crocodilians. They first appeared 95 million years ago in the Late Cretaceous period ( Cenomanian stage) and are the closest living ...
ns. A variety of early mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
s were present including multituberculate
Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...
s, marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a po ...
s, and insectivora
The order Insectivora (from Latin ''insectum'' "insect" and ''vorare'' "to eat") is a now-abandoned biological grouping within the class of mammals. Some species have now been moved out, leaving the remaining ones in the order Eulipotyphla, w ...
ns.
See also
* Timeline of hadrosaur research
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events.
Timelines can use any suitable scale representin ...
*2016 in paleontology
Flora Plants
Fungi
Cnidarians
Research
* '' Yunnanoascus haikouensis'', previously thought to be a member of Ctenophora, is reinterpreted as a crown-group medusozoan by Han ''et al.'' (2016).
* A study on the fossil corals from the Late Tri ...
References
{{Taxonbar, from=Q385949
Saurolophines
Late Cretaceous dinosaurs of North America
Taxa named by Lawrence Lambe
Grand Staircase–Escalante National Monument
Dinosaur Park fauna
Paleontology in Montana
Paleontology in Utah
Paleontology in Alberta
Kaiparowits Formation
Campanian genus first appearances
Campanian genus extinctions
Ornithischian genera