Gargoyleosaurus

*Gargoyleosaurus parkpini*

* Jurassic Park Institute Artwork
* Robert F Walters Artwork

***Gargoyleosaurus*** (meaning "gargoyle lizard") is one of the earliest ankylosaurs known from reasonably complete fossil remains. Its skull measures 29 centimetres (11 in) in length, and its total body length is an estimated 3 to 4 metres (9.8 to 13.1 ft). It may have weighed as much as 1 tonne (2,200 lb). The holotype was discovered at the Bone Cabin Quarry West locality, in Albany County, Wyoming in exposures of the Upper Jurassic (Kimmeridgian to Tithonian stages) Morrison Formation.

The type species, *G. parkpinorum* (originally *G. parkpini*) was described by Ken Carpenter et al. in 1998. A mounted skeletal reconstruction of *Gargoyleosaurus parkpinorum* can be seen at the Denver Museum of Nature and Science. *Gargoyleosaurus* was present in stratigraphic zone 2 of the Morrison Formation.

## Holotype

The holotype specimen of *Gargoyleosaurus parkpinorum* was collected by Western Paleontology Labs in 1995 and is currently held in the collections of the Denver Museum of Nature and Science, Denver, Colorado. Besides the holotype, two other partial skeletons are known (although not yet described). The holotype consists of most of the skull and a partial postcranial skeleton. The specimen was originally described as *Gargoyleosaurus parkpini* by Carpenter, Miles and Cloward in 1998, then renamed *G. parkpinorum* by Carpenter *et al.* in 2001, in accordance with ICZN art. 31.1.2A.

## Description

Gargoyleosaurus was a relatively small ankylosaur, reaching 3–3.5 m (9.8–11.5 ft) in length and 300–754 kg (661–1,662 lb) in body mass. Much of the skull and skeleton has been recovered, and the taxon displays cranial sculpturing, including pronounced deltoid quadratojugal and squamosal bosses. The taxon is further characterized by a narrow rostrum (in dorsal view), the presence of seven conical teeth in each premaxilla, an incomplete osseous nasal septum, a linearly arranged nasal cavity, the absence of an osseus secondary palate, and, as regards osteoderms, two sets of co-ossified cervical plates and a number of elongate conical spines. A very unusual feature is the sagittal (midline) osteoderm on the first set of cervical plates; in most other ankylosaurs, these osteoderms are bilateral, i.e. paired with one on each side of the midline.

## Classification

Much of the skull and skeleton has been recovered, and the taxon displays cranial sculpturing, including pronounced deltoid[disambiguation needed] quadratojugal and squamosal bosses. The taxon is further characterized by a narrow rostrum (in dorsal view), the presence of seven conical teeth in each premaxillae, an incomplete osseous nasal septum, a linerarly arranged nasal cavity, the absence of an osseus secondary palate, and, as regards osteoderms, two sets of co-ossified cervical plates and a number of elongate conical spines.

Vickaryous et al. (2004) place *Gargoyleosaurus parkpinorum* within the Family Ankylosauridae of the Ankylosauria and are in agreement with most previous phylogenetic hypotheses, which place the genus as the sister group to all other ankylosaurids (i.e., members of the Ankylosauridae). These studies however, only utilized the skull, whereas many of the distinctive features of the family Polacanthidae are in the postcranial skeleton.

## JPInstitute.com Description

Gargoyleosaurus was a smaller member of the family of armored dinosaurs that included Gastonia. Unlike its later relatives, it did not have a club on its tail. This dinosaur relied on large spikes that stuck out from its shoulders to defend itself. It was discovered in a very famous quarry called "Bone Cabin Quarry". Near the quarry is a small house that was built out of many fossil dinosaur bones!

Gargoyleosaurus may be the same as Mymoorapelta, another Late Jurassic ankylosaur.

## Dinosaur Field Guide Description

Gargoyleosaurus ("gargoyle lizard") is one of the rarest of the armored dinosaurs. It is from the jurassic Period, not the Cretaceous like most ankylosaurs. It has many primitive features. For example, in most ankylosaurs, the upper part of the beak has no teeth. The more teeth present in the beak, the more primitive the dinosaur. Gargoyleosaurus has seven teeth, more than in any other ankylosaur. Most ankylosaurs also have a set of large, folded nasal air passages. In Gargoyleosaurus, the small nasal air passage is straight. The most highly armored ankylosaurs have solid plates of bone (armor) on the outside of the body. In Gargoyleosaurus, they are hollow. Ankylosaurs and stegosaurs are classified together in a larger group called the Thyreophora, or "armored dinosaurs." They share the common feature known as "dermal armor." or armor that grows out of the skin.

### Fun Facts

The armor of Gargoyleosaurus looks amazingly like the painted and spiked fans at an Oakland Raiders football game!

### Trivia

The only Gangoyleosaurus skull and skeleton on display are in the Denver Museum of Natural History.

## Links

http://web.archive.org/web/20040606025643fw\_/http://www.jpinstitute.com/dinopedia/dinocards/dc\_gargo.html#