From Simple English Wikipedia, the free encyclopedia
Saurischia
is one of the two main groups of
dinosaurs
. In 1888,
Harry Seeley
classified
dinosaurs into two
orders
,
[3]
which are now generally considered unranked
clades
. Their
hip
structure
was why they were put into these groups. Saurischians ('lizard-hipped') and the
ornithischians
('bird-hipped') have differences in the ways bones in the hip are put together.
[4]
The saurischian
pubic bones
primarily pointed backward, while the ornithischian pubic bones pointed forward. Despite this pattern, the pubic bones of several saurschians, including
herrerasaurids
,
[5]
therizinosauroids
,
[6]
dromaeosaurids
,
[7]
and
birds
,
[8]
point forward. It's important consider than the etymology of names Saurischia and Ornithischia does not reflect the evolutionary relationships of these groups. Ornithischians were called 'bird-hipped' because their hips are similar to those of birds, but birds themselves evolved from 'lizard-hipped' saurischians.
[9]
Saurischia includes two main subgroups:
Theropoda
and
Sauropodomorpha
. Theropods are represented by bipedal, primarily
carnivorous
dinosaurs (such as
Tyrannosaurus
and
Velociraptor
). Birds are theropods and the only group of dinosaurs that has survive to the present day. Early sauropodomorphs were similar to early theropods because they shared a
common ancestor
. However, the most diverse group of sauropodomorphs,
Sauropoda
, was represented by long-necked
herbivorous
dinosaurs that often reached gigantic sizes (such as
Diplodocus
and
Brachiosaurus
).
[4]
- ↑
Langer, M.C.; Ramezani, J.; Da Rosa, A.A.S. (2018). "U-Pb age constraints on dinosaur rise from south Brazil".
Gondwana Research
.
X
(18): 133?140.
Bibcode
:
2018GondR..57..133L
.
doi
:
10.1016/j.gr.2018.01.005
.
- ↑
Nesbitt, S. J.; Barrett, P. M.; Werning, S.; Sidor, C. A.; Charig, A. J. (2013).
"The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania"
.
Biol. Lett
.
9
(1): 20120949.
doi
:
10.1098/rsbl.2012.0949
.
PMC
3565515
.
PMID
23221875
.
- ↑
Seeley, H.G. (1888). "On the classification of the fossil animals commonly named Dinosauria."
Proceedings of the Royal Society of London
,
43
: 165-171.
- ↑
4.0
4.1
Weishampel, Dodson & Osmolska 2004
, pp. 21?24, "Saurischia" by
Thomas R. Holtz Jr.
and
Halszka Osmolska
.
- ↑
Paul, Gregory S.
(1988).
Predatory Dinosaurs of the World: A Complete Illustrated Guide
. New York:
Simon & Schuster
. pp.
248
?250.
ISBN
978-0-671-61946-6
.
LCCN
88023052
.
OCLC
859819093
.
- ↑
Weishampel, Dodson & Osmolska 2004
, pp. 151?164, chpt. 7: "Therizinosauroidea" by James M. Clark,
Teresa Marya?ska
, and
Rinchen Barsbold
.
- ↑
Weishampel, Dodson & Osmolska 2004
, pp. 196?210, chpt. 10: "Dromaeosauridae" by Peter J. Makovicky and
Mark A. Norell
.
- ↑
Weishampel, Dodson & Osmolska 2004
, pp. 210?231, chpt. 11: "Basal Avialae" by
Kevin Padian
.
- ↑
Brusatte, Stephen L.
(2012).
Dinosaur Paleobiology
. New York: Wiley, J. pp. 20?21.
ISBN
978-0-470-65658-7
.