''Zephyrosaurus'' (meaning "westward wind lizard") is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of orodromine ornithischian

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

. It is based on a partial skull and

postcrania The postcranium ("behind the cranium"; plural: postcrania) or postcranial skeleton in zoology and vertebrate paleontology is the skeleton apart from the skull. The postcranium encompasses the axial skeleton, which includes the entirety of the verte ...

l fragments discovered in the

Aptian The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

-age

Lower Cretaceous Lower may refer to: * ''Lower'' (album), 2025 album by Benjamin Booker * Lower (surname) * Lower Township, New Jersey *Lower Receiver (firearms) * Lower Wick Gloucestershire, England See also * Nizhny {{Disambiguation ...

Cloverly Formation of Carbon County,

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

, USA. New remains are under description, and tracks from

Maryland Maryland ( ) is a U.S. state, state in the Mid-Atlantic (United States), Mid-Atlantic region of the United States. It borders the states of Virginia to its south, West Virginia to its west, Pennsylvania to its north, and Delaware to its east ...

and

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, also in the US, have been attributed to animals similar to ''Zephyrosaurus''. It lived approximately 113 mya.

Discovery and history

Hans-Dieter Sues Hans-Dieter Sues (born 1956) is a German-born American palaeontologist who is a Senior Research Geologist and Curator of Vertebrate Paleontology at the National Museum of Natural History of the Smithsonian Institution in Washington, DC. Career ...

named his new genus in recognition of the fossil being found in western

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, and Charles R. Schaff, who found the specimen. MCZ 4392, the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

specimen, is composed of

jaw The jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth ...

fragments, the

braincase In human anatomy, the neurocranium, also known as the braincase, brainpan, brain-pan, or brainbox, is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calv ...

and associated bones, several partial

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e, and rib fragments. He found the new genus to represent a previously unknown lineage of hypsilophodont (a taxon now considered not natural), similar in some respects to ''

Hypsilophodon ''Hypsilophodon'' (; meaning "high-crested tooth") is a neornithischian dinosaur genus from the Early Cretaceous period of England. It has traditionally been considered an early member of the group Ornithopoda, but recent research has put this ...

''. Because of the fragmentary nature of the type, and lack of additional remains, ''Zephyrosaurus'' had not attracted much attention until recently, when two separate events brought it more recognition. First, Martha Kutter, in a 2003 abstract, reported on new remains of this genus under study at the

Sam Noble Oklahoma Museum of Natural History The Sam Noble Oklahoma Museum of Natural History is the officially designated natural history museum for the State of Oklahoma, located on the campus of the University of Oklahoma. The museum was founded in 1899 by an act of the Oklahoma Terri ...

, including the remains of at least seven individuals with bones from all regions of the body. Then, Stanford ''et al.'' (2004) published on dinosaur tracks from the Patuxent Formation of Maryland and Virginia, which they named '' Hypsiloichnus marylandicus'' and attributed to an animal akin to ''Zephyrosaurus'' based on the proportions of the hands and feet.

Description

''Zephyrosaurus'' is still very incompletely known. Among other distinctive characteristics, it had a steep face, a raised knob on the upper jaw, and a larger knob on the

cheekbone In the human skull, the zygomatic bone (from ), also called cheekbone or malar bone, is a paired irregular bone, situated at the upper and lateral part of the face and forming part of the lateral wall and floor of the orbit (anatomy), orbit, of t ...

. Some of the bones may have allowed movement within the skull (cranial kinesis) as well. Like other orodromines, it had

beak The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for pecking, grasping, and holding (in probing for food, eating, manipulating and ...

teeth.

Classification

Several studies have suggested that ''Zephyrosaurus'' and '' Orodromeus'' are closely related, mostly by virtue of both having bosses on their cheeks. Other studies have had difficulty classifying it, due to the sparseness of the original material. '' Oryctodromeus'' also shares several characteristics with ''Zephyrosaurus'' and ''Orodromeus'', some of which may be related to

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

ing. Phylogenetic analysis in the 2010s has classified ''Zephyrosaurus '' as part of the Thescelosauridae family.

Paleobiology

''Zephyrosaurus'' would have been a small, swift,

biped Bipedalism is a form of terrestrial locomotion where an animal moves by means of its two rear (or lower) 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'' ' ...

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

. Like ''Orodromeus'' and ''Oryctodromeus'', it may have burrowed as well.

References

External links

Press release
for ''Hypsiloichnus marylandicus''.

on what would become ''Hypsiloichnus marylandicus''.
Photograph of a ''Hypsiloichnus marylandicus'' footprint
fro
The Paleontology Portal

''Zephyrosaurus''
in The Natural History Museum's Dino Directory. {{Taxonbar, from=Q187013 Thescelosauridae Dinosaur genera Aptian dinosaurs Albian dinosaurs Cloverly Formation Dinosaurs of the United States Fossil taxa described in 1980 Taxa named by Hans-Dieter Sues