lecture 13: Theropoda part 1

Question 1

Theropods, general description

Answer 1

Have been present since the late triassic, they were obligate bipeds, often carnivorous, relatively large brained and only group of dinosaurs with living members

Question 2

What was the first non bird theropod?

Answer 2

Megalosaurus

Question 3

What was the first Theropod in North America?

Answer 3

Deinodon, Troodon

Question 4

What was the first complete fossil found?

Answer 4

compsognathus

Question 5

First feathered theropod?

Answer 5

Archaeopteryx

Question 6

Theropoda named by O.C. marsh, at first only included one family, called?

Answer 6

Allosauridae

It is now the most inclusive clade

Question 7

Proposed distinguishing features for theropoda

Answer 7

• Intramandibular joint in lower jaw
• Hollow bones
• hands with reduced or absent outer digits, long phalanges and hooked claw
• End of pubis narrow side to side

Question 8

Theropod origins

Answer 8

Ischigulasto formation of Argentina

Diverse early dinosaurs: Herrerasaurus, eoraptor, eodromaeus

Question 9

Neotheropoda

Answer 9

“new theropods”, oldest are about 220 mya, co existed with non-neotheropod carnivorous dinosaurs
Distinguishing features:
-Furcula (wishbone) present
-longer illium and sacrum present
-1st metatarsal short, does not articulate with ankle

Question 10

What is the best known triassic theropod?

Answer 10

Coelophysis

Question 11

Coelophysis at Ghost Ranch, NM

Answer 11

Lots of individuals of varying size, good articulation
Sexual dimorphism proposed for adults: gracile and robust morph
Stomach contents include small crocodylomorph archosaur

Question 12

Predators of triassic theropods

Answer 12

Large terrestial archosaurs related to crocodiles (prestosuchus)

Question 13

End- triassic extinctions

Answer 13

Complex faunal changes in terrestial realm, not a single and sudden mass extinction
Extinction of:
-non crocodylomorph croc relatives
-non neotheropod carnivorous dinosaurs

Question 14

Early Jurassic

Answer 14

theropods dominate the land

Question 15

Early jurassic tracks

Answer 15

Megatheropod tracks reported from Lesotho, southern Africa. Allosaurid like theropod

Question 16

Early jurassic ichnolagerstatte

Answer 16

St. george utah, tracks of wading and swimming theropods inhabiting a lakeshore environment

Question 17

The middle jurassic

Answer 17

Second major radiation of theropods

Question 18

Major Faunal turnover

Answer 18

Early jurassic: “prosauropods” as the dominant terrestial herbivores; a few primitve sauropods and ornithischians
Middle jurassic: no more “prosauropods” earliest examples of Stegaurs, ankylosaurs, ornithopods,neosauropods

Question 19

Averostra

Answer 19

“bird snout”
Completely replaced all earlier theropod lineages
Unites two theropod clades that would exist for the rest of the mesozoic: ceratosauria and tetanurae

Question 20

Tetanurae

Answer 20

“stiff tail”- Elongation of interlocking projections called zygopophyses
Enlarged hand with modified wrist and only 3 digits, large claw on inner digit. Megalosaurus, early member of tetanurae

Question 21

Proceratosaurus

Answer 21

Single specimen found in England
oldest known Coelurosaur
early member of tyrannosauroidea: about 100 mya older than tyrannosaurus rex

Question 22

Megalosaurs common in ______ environments and Allosaurids more ______ inland

Answer 22

Nearshore; inland

Question 23

the late jurassic

Answer 23

Great diversity of body size & types, first birds

Question 24

Ceratosauria

Answer 24

Diverse averostrans with often bizarre skulls, small hands with 4 stubby digits

Question 25

Beaked, herbivorous theropods

Answer 25

Limusaurus (ceratosauria) is te oldest known theropod with a toothless beak- but only as an adult. Juvenilles start out with full set of teeth
Dietary shift towards greater herbivory with age

Question 26

Yanliao Biota

Answer 26

Jurassic Lagerstatte in Chine, oldest known feather preservation in theropods
First examples of extreme miniaturization

Question 27

Anchiornis

Answer 27

over 200 individuals collected, long pennaceous feathers on arms and legs

Question 28

Serikornis

Answer 28

Named in 2017, silky plumage without barbules, unable to fly

Question 29

scansoriopterygidae

Answer 29

tiny climbers with exaggerated third finger, Yi with long rods on wrists to support a wing membrane

Question 30

Solnhofen limestone, germany, what is traditionally the first bird?

Answer 30

Archaeopteryx

Question 31

Allosaurus

Answer 31

Marsh’s original theropod. Most abundant large predator in late jurassic of north america. Dozens colected in Cleveland lloyd quarry. Narrow hatchet shaped skull, downward slashing neck

Question 32

Morrison formation theropods

Answer 32

ceratosaurs, megalosaurs, allosaurs, tyrannosauroids, other coleurosaurs

Question 33

Oldest theropod nest found in _______

Answer 33

portugal; about 100 eggs and embryonic bones attributed to a tetanuran