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''Leptoceratops'' (meaning 'Thin-horned face' and derived from Greek ''lepto-/λεπτο-'' meaning 'small', 'insignificant', 'slender', 'meagre' or 'lean', ''kerat-/κερατ-'' meaning 'horn' and ''-ops/ωψ'' meaning face), is a genus of leptoceratopsid
ceratopsian 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 Jurassi ...
dinosaurs from the late Cretaceous
Period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...
(late Maastrichtian age, 68.8-66 Ma ago) of what is now Western North America. Their skulls have been found 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 Terri ...
, Canada and Wyoming.


Description

''Leptoceratops'' could probably stand and run on their hind legs: analysis of forelimb function indicates that even though they could not
pronate Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...
their hands, they could walk on four legs. Paul proposed that ''Leptoceratops'' was around long and could have weighed , but Tereschenko proposed a maximum length of .


Discovery and species

The first small ceratopsian named ''Leptoceratops'' was discovered in 1910 by
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 ...
in the
Red Deer Valley Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondary ...
in Alberta, Canada. He described it four years later. The first specimen had a part of its skull missing, but there were later well-preserved finds by C. M. Sternberg in 1947, including one complete fossil. Later material was found in 1978 in the Bighorn Basin of northern Wyoming. The type species is ''Leptoceratops gracilis''. In 1942, material collected in Montana was named ''Leptoceratops cerorhynchos,'' but this was later renamed ''
Montanoceratops ''Montanoceratops'' is an extinct genus of small ceratopsian dinosaur that lived approximately 70 million years ago during the latter part of the Cretaceous Period in what is now Montana and Alberta. ''Montanoceratops'' was a small sized, moder ...
''.


Classification

''Leptoceratops'' belonged to the Ceratopsia, a group of herbivorous dinosaurs with parrot-like beaks that thrived in North America and
Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
during the Cretaceous Period. Although traditionally allied with the Protoceratopsidae, it is now placed in its own family,
Leptoceratopsidae Leptoceratopsidae is an extinct family of neoceratopsian dinosaurs from Asia, North America and Europe. Leptoceratopsids resembled, and were closely related to, other neoceratopsians, such as the families Protoceratopsidae and Ceratopsidae, bu ...
, along with dinosaurs such as ''
Udanoceratops ''Udanoceratops'' (meaning "Udan's horned face") is a genus of large leptoceratopsid dinosaur that lived during the Late Cretaceous period of Mongolia, in what is now the Djadokhta Formation. Discovery ''Udanoceratops'' was first named and de ...
'' and ''
Prenoceratops ''Prenoceratops'', (meaning 'bent or prone-horned face' and derived from Greek ''prene-/πρηνη-'' meaning 'bent forwards' or 'prone', ''cerat-/κερατ-'' meaning 'horn' and ''-ops/ωψ'' meaning 'face') is a genus of ceratopsian dinosaur f ...
''. The relationships of Leptoceratops to
ceratopsids Ceratopsidae (sometimes spelled Ceratopidae) is a family of ceratopsian dinosaurs including ''Triceratops'', ''Centrosaurus'', and ''Styracosaurus''. All known species were quadrupedal herbivores from the Upper Cretaceous. All but one species ar ...
are not entirely clear. Although most studies suggest that they lie outside the protoceratopsids and ceratopsids, some studies suggest that they may be allied with Ceratopsidae. The absence of
premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has ...
ry teeth is one feature that supports this arrangement.


Paleobiology


Behavior

In 2019, fossils from the Hell Creek Formation found three fossil bone beds which revealed that not only was ''Leptoceratops'' a social animal, but also raised its young in burrows.


Diet

''Leptoceratops'', like other ceratopsians, would have been a
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 mouthp ...
. The jaws were relatively short and deep, and the jaw muscles would have inserted over the large parietosquamosal frill, giving ''Leptoceratops'' a powerful bite. The teeth are unusual in that the dentary teeth have dual wear facets, with a vertical wear facet where the maxillary teeth sheared past the crown, and a horizontal wear facet where the maxillary teeth crushed against the dentary teeth. This shows that ''Leptoceratops'' chewed with a combination of shearing and crushing. Between the shearing/crushing action of the teeth and the powerful jaws, ''Leptoceratops'' was probably able to chew extremely tough plant matter. Given its small size and quadrupedal stance, ''Leptoceratops'' would have been a low feeder. Flowering plants, also known as angiosperms, were the most diverse plants of the day, although
ferns A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except th ...
,
cycads Cycads are seed plants that typically have a stout and woody ( ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ...
and
conifers Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All exta ...
may still have been more common in terms of numbers. A 2016 study revealed that ''Leptoceratops'' was able to chew its food much like several groups of mammals, which meant that it had a diet that consisted of tough, fibrous plant material.


See also

*
Timeline of ceratopsian research This timeline of ceratopsian research is a chronological listing of events in the History of paleontology, history of paleontology focused on the ceratopsians, a group of herbivorous marginocephalian dinosaurs that evolved parrot-like beaks, bon ...


References

* B. Brown. 1914. Leptoceratops, a new genus of Ceratopsia from the Edmonton Cretaceous of Alberta. Bulletin of the American Museum of Natural History 33(36):567-580


Sources

* * {{Taxonbar, from=Q131328 Leptoceratopsids Late Cretaceous dinosaurs of North America Fossil taxa described in 1914 Taxa named by Barnum Brown Lance fauna Hell Creek fauna Scollard fauna Paleontology in Alberta Paleontology in Wyoming Maastrichtian genus first appearances Maastrichtian genus extinctions Ornithischian genera