From Simple English Wikipedia, the free encyclopedia
Ankylosaurs
were herbivorous armoured dinosaurs in the order
Ornithischia
. Their armour was made of
scutes
(bony scales). They were quadrupeds with short and strong legs. Fossils of Ankylosaurs have been found on every continent. They were of two types:
- Ankylosauria
- Ankylosauridae
: armoured from their head to their club-ended tail.
- Nodosauridae
: no tail club but spikes and bony bumps on body.
They first appeared in the
Middle Jurassic
,
[1]
and lived until the end of the
Cretaceous period
.
When adult, they were large:
Edmontonia
was bulky, broad and
tank
-like. Its length when adult was about 6.6 m (22 ft).
[2]
Both main
Edmontonia
species,
E. longiceps
and
E. rugosidens
weighed about three tonnes.
[3]
Ankylosaurs were low to the ground. The large
hyoid
bones left in skeletons shows they had long, flexible tongues. They also had a large, side
secondary palate
. This means that they could breathe while chewing.
Their huge gut suggests they
fermented
their food, using
symbiotic
bacteria and
gut flora
. Their diet was mainly
ferns
and
cycads
, which were hugely widespread, especially in the
Lower Jurassic
. The tropical climate supported plant growth, as it does today. Ankylosaurs fed on vegetation at or below the height of a meter.
[4]
An unresolved question is whether they could feed higher than their usual mouth level, by raising the front of their body somewhat. This possibility which would give them access to many tree ferns and cycads which would otherwise be out of reach. Given the unevenness of terrain, there might be places they could stand on higher ground, and eat plants normally out of reach.
Ankylosaurs got some protection, not just from their armour, but from their being a miserable reward from the carnivore's point of view. They were signalling something like "I'm going to be tough to kill and poor to eat".
Most ankylosaurs have been found in
Laurasia
.
[5]
The first definitive ankylosaur to be recognized from
Gondwana
was discovered in
Australia
in 1964 and later named in 1980 as
Minmi paravertebra
. Ankylosaurs would be expected to live in heavily wooded areas.
- ↑
But see
Yuxisaurus
- ↑
Edmontonia
in: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B.
The Age of Dinosaurs
. Publications International, p141.
ISBN 0-7853-0443-6
- ↑
Paul G.S. 2010,
The Princeton Field Guide to Dinosaurs
, Princeton University Press p. 238
- ↑
Mallon, Jordan C; David C Evans; Michael J Ryan; Jason S Anderson (2013).
"Feeding height stratification among the herbivorous dinosaurs from the Dinosaur Park Formation (upper Campanian) of Alberta, Canada"
.
BMC Ecology
.
13
: 14.
doi
:
10.1186/1472-6785-13-14
.
PMC
3637170
.
PMID
23557203
.
- ↑
Note: Ankylosauria = formal name; ankylosaurs a general term. Comparison: Dinosauria vs dinosaurs.