Archaeornithoides

Taxobox|
name = "Archaeornithoides"
fossil_range = Late Cretaceous
regnum = Animalia
phylum = Chordata
classis = Sauropsida
superordo = Dinosauria
ordo = Saurischia
subordo = Theropoda
unranked_familia = Coelurosauria
genus = "Archaeornithoides"
genus_authority = Elzanowksi & Wellnhofer, 1992
subdivision_ranks = Species
subdivision =
* "A. deinosauriscus" Elzanowski & Wellnhofer, 1992 (type)

"Archaeornithoides" is a genus of maniraptoriform theropod dinosaur. It was found in Late Cretaceous river sandstones of the Djadokhta Formation beds located in Bayn Dzak, Mongolia. The remains, consisting of a juvenile skull fragment comprehending paired maxillae and dentaries and also palate bones were described by Elzanowski and Wellnhofer in 1992 [cite journal |last=Elżanowski |first=Andrzej |authorlink= |coauthors=Wellnhofer, Peter |year=1992 |month= |title=A new link between theropods and birds from the Cretaceous of Mongolia |journal=Nature |volume=359 |issue= |pages=821–823 |doi=10.1038/359821a0 |url= |accessdate= |quote= ] and 1993.cite journal |last=Elżanowski |first=Andrzej |authorlink= |coauthors=Wellnhofer, Peter |year=1993 |month= |title=Skull of Archaeornithoides from the Upper Cretaceous of Mongolia |journal=American Journal of Science |volume=293 |issue= |pages=235–252 |id= |url=http://earth.geology.yale.edu/~ajs/1993/11.1993.08Elzanowski.pdf |accessdate= |quote= ]

The generic name ("Archaeornithoides") means “shaped like an ancient bird” in ancient Greek. The species name ("deinosauriscus") alludes to the animal's small size for a dinosaur.

Elżanowski & Wellnhofer (1993) suggested that "Archaeornithoides" was the closest known relative to birds Avialae. This conclusion rested on key bird-like features; an interdigitated suture between the premaxilla and maxilla, broad palatal shelves, pneumatic sinuses, lack of interdental plates, and unserrated teeth. Since publication, though, all of these features have been discovered in new fossils of adult and/or juvenile troodonts and dromaeosaurs. Clark, James M., Norell, Mark A., Makovicky, Peter J. (2002) "Cladistic approaches to the relationships of birds to other theropods" pp.31-61 in “Mesozoic Birds: Above the Heads of Dinosaurs” Chiappe&Witmer ed. ISBN 0-520-20094-2]

Elzanowski and Wellnhofer noted that the specimen has distinct bite marks, and suggested that it may have been bitten off of the braincase by a deltatheridiid ("Deltatheridium") mammal the size of a weasel (adding that these are common in the Bayn Dzak assemblage). Clark and colleagues (2002) noted that it may have also passed through the digestive tract of the predator before fossilization. If true, this may be the first known evidence of Mesozoic mammals eating dinosaurs (see Repenomamus).

References

External links

* [http://www.dinodata.org/index.php?option=com_content&task=view&id=5937&Itemid=67 "Archaeornithoides"] at DinoData