Agnosphitys Fraser, Padian, Walkden & Davis, 2002
Agnosphitys Fraser, Padian, Walkden & Davis, 2002
(Palaeontology (Oxf) 45 (1), January: 80
NcZ) "unknown begetter"
ag-noh-SFIE-tis (Gr. agnos "unknown" + Gr. phitys "begetter") (m)
named "with reference to the position of the new form relative to the Dinosauria"
--depending on how the group Dinosauria is defined, Agnosphitys is either
a small primitive meat-eating dinosaur, or a dinosauriform more advanced than herrarasaurs
but not a true dinosaur. Agnosphitys was probably around 70 cm (28 in) long
and is based on a left ilium (Holotype: VMNH 1745 (Virginia Museum of Natural History,
Martinsville, Virginia)), plus referred material (left maxilla with serrated teeth,
left and right astragaluses, right humerus, 2 sacral vertebrae, isolated tooth),
found in the Late Triassic Cromhall Quarry, Avon, southwest England.
In common with true dinosaurs, it has a brevis fossa on the ilium,
a semi-perforate acetabulum under the ilium, and a reduced astragulus
with an ascending process in its ankle bones; however, it appears to have only
2 sacral vertebrae (true dinosaurs have at least 3 sacral vertebrae).
Agnosphitys has more dinosaurian features than Herrarasaurus,
a form that also has only 2 sacral vertebrae and that many researchers consider a true dinosaur.
However, other researchers dispute definitions of the Dinosauria that would
include Herrarasaurus, which they classify as a dinosauriform rather than a true
dinosaur--whether Agnosphitys should be a classified a true dinosaur
or as a dinosauriform remains a point of debate.
Type Species: Agnosphitys cromhallensis [krom-haw-LEN-sis]
Fraser, Padian, Walkden & Davis, 2002: "from Cromhall (Quarry)" in England.
Dinosauromorpha Dinosauria(?) Late Triassic Europe [added 6-2002]
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