![Wannanosaurus yansiensis](https://upload.wikimedia.org/wikipedia/commons/e/ed/Wannanosaurus_yansiensis.png)
''Wannanosaurus'' (meaning "
Wannan lizard", named after the location where it was discovered) is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
basal pachycephalosauria
Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. With the exception of two species, most pachycephal ...
n
dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...
from the
Maastrichtian
The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...
Upper Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
Xiaoyan Formation, about 80 million years ago (
mya) in what is now
Anhui
Anhui , (; formerly romanized as Anhwei) is a landlocked province of the People's Republic of China, part of the East China region. Its provincial capital and largest city is Hefei. The province is located across the basins of the Yangtze River ...
,
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. The
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
, ''Wannanosaurus yansiensis'', was described by Hou Lian-Hai in 1977.
It is known from a single partial skeleton, including a partial
skull roof
The skull roof, or the roofing bones of the skull, are a set of bones covering the brain, eyes and nostrils in bony fishes and all land-living vertebrates. The bones are derived from dermal bone and are part of the dermatocranium.
In comparati ...
and lower jaw, a
femur
The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...
and
tibia
The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...
, part of a rib, and other fragments. Because it has a flat skull roof with large openings, it has been considered primitive among pachycephalosaurs.
Sometimes it has been classified as a member of the now-deprecated family
Homalocephalidae,
now thought to be an unnatural assembly of pachycephalosaurians without domed skulls.
[
Although its remains are from a very small individual, with a femur length of ~8 centimeters (3.1 in) and an estimated overall length of about 60 cm (2 ft),][Holtz, Thomas R. Jr. (2011) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,']
Winter 2010 Appendix.
/ref> the fused bones in its skull suggest that it was an adult at death. Like other pachycephalosaurians, it was probably herbivorous
A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...
or omnivorous
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...
, feeding close to the ground on a variety of plant matter, and possibly insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s as well.[
]
See also
* Timeline of pachycephalosaur research
This timeline of pachycephalosaur research is a chronological listing of events in the history of paleontology focused on the pachycephalosaurs, a group of dome-skulled herbivorous marginocephalian dinosaurs. One of the first major events related ...
References
External links
Dinodictionary web site
{{Taxonbar, from=Q133138
Pachycephalosaurs
Ornithischian genera
Maastrichtian genera
Late Cretaceous dinosaurs of Asia
Fossil taxa described in 1977