Zephyrosaurus

Taxobox
name = "Zephyrosaurus"
fossil_range = Lower Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Ornithischia
subordo = Cerapoda
infraordo = Ornithopoda
familia = Hypsilophodontidae
genus = "Zephyrosaurus"
genus_authority = Sues, 1980
subdivision_ranks = Species
subdivision =
* "Z. schaffi" Sues, 1980 (type)

"Zephyrosaurus" (meaning "westward wind lizard") is a genus of hypsilophodont ornithopod dinosaur. It is based on a partial skull and postcranial fragments discovered in the Aptian-Albian-age Lower Cretaceous Cloverly Formation of Carbon County, Montana. New remains are under description, and tracks from Maryland and Virginia have been attributed to something like it.

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. Some of the bones may have allowed movement within the skull (cranial kinesis) as well. Like other hypsilophodonts, it had beak teeth.cite journal |last=Sues |first=Hans-Dieter |year=1980 |title=Anatomy and relationships of a new hypsilophodontid dinosaur from the Lower Cretaceous of North America |journal=Palaeontographica Abteilung A Palaeozoologie-Stratigraphie |volume=169 |issue=1-3 |pages=51–72]

Classification

Several studies have suggested that "Zephyrosaurus" and "Orodromeus" are closely related, mostly by virtue of both having bosses ( [http://dml.cmnh.org/1999May/msg00106.html described informally] as "somewhat like an altoid") on their cheeks.cite journal |last=Weishampel |first=David B. |authorlink=David B. Weishampel |coauthors=and Heinrich, Ronald E. |year=1992 |title=Systematics of Hypsilophodontidae and Basal Iguanodontia (Dinosauria: Ornithopoda) |journal=Historical Biology |volume=6 |pages=159–184 |url=http://www.tandf.co.uk/journals/pdf/ghbi_06_01_01.pdf |accessdate=2007-03-10 ] cite book |last=Buchholz |first=Peter W. |title=The Mesozoic in Wyoming, Tate 2002 |year=2002 |publisher=The Geological Museum, Casper College |location=Casper, Wyoming |pages=18-34 |chapter=Phylogeny and biogeography of basal Ornithischia] Other studies have had difficulty classifying it, due to the sparseness of the original material.cite book |last=Norman |first=David B. |authorlink=David B. Norman |coauthors=Sues, Hans-Dieter; Witmer, Larry M.; and Coria, Rodolfo A. |editor=Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.)|title=The Dinosauria |edition=2nd |year= 2004|publisher=University of California Press |location=Berkeley |isbn=0-520-24209-2 |pages=393–412 |chapter=Basal Ornithopoda] "Oryctodromeus" also shares several characteristics with "Zephyrosaurus" and "Orodromeus", some of which may be related to burrowing. Thus, there may be a possible clade of burrowing hypsilophodonts from the middle to Late Cretaceous of Montana.cite journal |last=Varricchio |first=David J. |coauthors=Martin, Anthony J.; and Katsura, Yoshihiro |year=2007 |title=First trace and body fossil evidence of a burrowing, denning dinosaur |journal=Proceedings of the Royal Society B: Biological Sciences |volume=274 |pages=1361–1368 |doi=10.1098/rspb.2006.0443 |url=http://journals.royalsociety.org/content/uj1k12wh01587821/fulltext.pdf |accessdate=2007-03-22 ]

Discovery and history

Hans-Dieter Sues named his new genus in recognition of the fossil being found in western North America, and C. R. Schaff, who found the specimen. MCZ 4392, the type specimen, is composed of jaw fragments, the braincase and associated bones, several partial vertebrae, and rib fragments. He found the new genus to represent a previously unknown lineage of hypsilophodont, similar in some respects to "Hypsilophodon".

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, including the remains of at least seven individuals with bones from all regions of the body.cite journal |last=Kutter |first=M.M. |year=2003 |title=New material of "Zephyrosaurus schaffi" (Dinosauria:Ornithischia) from the Cloverly Formation (Aptian-Albian) of Montana |journal=Journal of Vertebrate Paleontology |volume=23 |issue=3, Suppl. |pages=69A]

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.cite journal |last=Stanford |first=R. |coauthors=Weems, R.; and Lockley, M. |year=2004 |title=A new dinosaur ichnotaxon from the Lower Cretaceous Patuxent Formation of Maryland and Virginia |journal=Ichnos |volume=11 |issue=3-4 |pages=251–259 |doi=10.1080/10420940490428797]

Paleobiology

"Zephyrosaurus" would have been a small, swift, bipedal herbivore. Like "Orodromeus" and "Oryctodromeus", it may have burrowed as well.

References

External links

* [http://dml.cmnh.org/2005Jan/msg00095.html Press release] for "Hypsiloichnus marylandicus".
* [http://dml.cmnh.org/1999Sep/msg00072.html Dinosaur Mailing List discussion] on what would become "Hypsiloichnus marylandicus".
* [http://www.paleoportal.org/index.php?globalnav=fossil_gallery&sectionnav=detail&submission_id=1070&taxon_id=&state_id=&period_id=18&assemblage_id=&last_section=search Photograph of a "Hypsiloichnus marylandicus" footprint] , from [http://www.paleoportal.org/index.php The Paleontology Portal] .
* [http://internt.nhm.ac.uk/jdsml/nature-online/dino-directory/detail.dsml?Genus=Zephyrosaurus&showTaxonomy=yes&identifier=zephyro&&beginIndex=&section=home "Zephyrosaurus"] in The Natural History Museum's Dino Directory.