| Cruxicheiros | |
|---|---|
 | |
| Vertebrae | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | Theropoda |
| Clade: | Tetanurae |
| Genus: | †Cruxicheiros Benson & Radley,2010 |
| Species: | †C. newmanorum |
| Binomial name | |
| †Cruxicheiros newmanorum Benson & Radley, 2010 | |
Cruxicheiros (meaning "cross hand") is agenus oftheropoddinosaur which lived in theMiddle Jurassic ofEngland. Thetype species isC. newmanorum, described byRoger Benson andJonathan Radley in 2010.[1]
The remains of theholotype were discovered in the early 1960s in the Cross Hands Quarry, nearLittle Compton, inWarwickshire in England. These fossils came from theChipping Norton Limestone Formation, which is dated to the lowerBathonianstage of theMiddle Jurassic, about 167 mya (million years ago). The fossils were stored in theBirmingham Museum and Art Gallery until 2008 when they were transferred to theWarwickshire Museum Service; the transfer prompted closer study of the neglected fossils.[1]
Unrecognized fossils of dinosaurs, many of them theropods, had been discovered in England at least as early as 1677. The larger theropod fossils had been attributed (without critical examination) toMegalosaurus, while the smaller ones were assigned toIliosuchus. The 2010 paper recognized differences between the Cross Hands Quarry discovery and those attributed toMegalosaurus. These differences include lower and broader spines along the animal's back, and differences in leg and hip bones.[1] The authors renamed the Cross Hands Quarry specimensCruxicheiros newmanorum; the generic nameCruxicheiros comes from a mixture ofLatin andGreek, Latincrux meaning "cross" and Greekcheir meaning "hand", in reference to the Cross Hands Quarry locality where the fossils were discovered. Thespecific namenewmanorum honors the Newman family, who own the quarry.[1]
Cruxicheiros was a large theropod, but the known material is very limited. Theholotype, cataloged as WARMS G15770, is a partial rightfemur. Additional material from the site probably comes from the same individual as the holotype, based on examination of the matrix of sandy limestone and calcite which make up all the fossils. The additional material consists of "an anterior dorsal or posterior cervical vertebra; a dorsal neural arch; a partial dorsal vertebra; the anterior half of a middle-distal caudal vertebra; a partial right scapulocoracoid; a partial left ilium; the proximal end of a left pubis; [and] numerous rib and bone fragments".[1] In 2012Thomas Holtz estimated its length at 9 meters (29.5 feet).[2]
Cruxicheiros was atetanuran, a member of the dinosaur group Tetanurae which also includes theropods such asTyrannosaurus andSpinosaurus. The describers did not placeCruxicheiros in any family. They performed acladistic analysis which rendered three equally probable positions forCruxicheiros: as the most basalneotetanuran (the line which gave rise to dinosaurs likeAllosaurus andbirds), as the most basalmegalosauroid (the line which led toMegalosaurus andSpinosaurus), or as the most basal member of the Tetanurae, whose earliest members must have predated the split between these theropod groups. In view of the uncertainties they classifiedCruxicheiros as Tetanuraeincertae sedis.[1]
.jpg)
.jpg)
.png)
.jpg)
