Module 14 Flashcards
Who was the first person to illustrate a dino femur in 1677
who identified the teeth, jaw and limbs of an ‘ancient lizard’ as Megalosaurus in 1824
who officially named the family of fossils we now know as the dinosaurs as ‘Dinosauria’, meaning terrible lizard in 1842
- Robert plot
- William Buckland
- Richard Owen
what group of reptiles did dinos evolve form and when
Archosaurs near end late Tri
- some suspect divergence occur earlier in late Tri ~230ma
what are the 2 broad groups dinos
whats the diff
Saurischia (forward pubis bone) and the Ornithischia (backwards pubis bone)
Saurischia
- name meaning
- pubis bone orientation
- incl what dino
- dominated when
- ‘lizard hipped’ dinosaurs
- forward pubis bone
- incl 2 leg theropods (t rex), sauropods
- dominate Tri/Jur dino pop
Ornithischia
- name meaning
- pubis bone orientation
- incl what dinos
- common when
- bird hipped dino
- pubis bone pionts backward
- hadrosaurs and Triceratops
- common Cre
ex of an archosaur
Euparkeria
early Tri in S Africa
~50cm
could run 2 legs short distrance
what does new research say about clasification of dinos
Saurischia and Ornithoscelida now
Ornithoscelida incl traditional ornithischians and the theropods
Coelophysis
- one earlies dinos
- lived late tri in reas w/ drought/ lots flash flooding
- carnivore
1.With respect to morphology, what are the three main ways in which Coelophysis differ from their reptile ancestors?
2.List 3 characteristics that contributed to Coelophysis being an excellent predator.
3.Using a chronological list of 3 steps, explain what is believed to have happened during the rapid burial of Coelophysis at Ghost Ranch.
5.What approximate speed is thought to be a normal walking pace for an adult Coelophysis? (in km/hr)
6.What approximate speed is thought to the fastest that an adult Coelophysis could have run? (in km/hr)
7.What size were fully grown Coelophysis relative to most adult dinosaurs?
8.How can paleontologists tell how old a specific Coelophysis was when it died?
9.What specific evidence suggests that Coelophysis may have been a cannibal? Why does further study bring this hypothesis in to question? (Hint: be specific)
1.What are some possible explanations for the ‘Predator Gap’, where there are virtually no medium sized predators in the fossil record?
2.How much did “small” predatory dinosaurs weigh?
3.How long did T. rex potentially live for?
4.If the two medium predator skeletons identified by some as Nanotyrannus, do end up belonging to a juvenile T. rex, what new information does this give us about T. rex?
5.What does the information from Question 4 suggest about the prey each of these different aged T. rex groups have hunted?
6.How might the answer to Question 5 help explain the gap in medium sized predators?
how to estimate the size of the muscle
size attachment areas on bone
muscles scars on bone
how to tell skin texture in dino
skin impressions
- lots show scales in many patterns
how to tell skin colour in dino
from pigment structures called meanosomes with diff shapes mean diff colours
- round= russets
- elongated= blck/grey
where dino frills/fringes brighly coloured?
yes
what is suggestion that feathers evolved for?
dispay
1.Describe the color pattern called ‘countershading’.
2.What does the shading on the animal’s body suggest about where it lived? Why?
3.Why was this type of shading likely to protect against predators?
4.How could further research in to color patterns help us better understand predators?
1.When did ‘protofeathers’ likely first arise?
2.Did some genera of the therapods include members with feathers?
3.Did some genera of the ornithischians include members with feathers?
4.What is Phylogenetic Bracketing?
5.Why did dinosaurs potentially develop feathers? (What are some of the potential functions of feathers?)
what is the most common place for dinos to live
how where they well adapted for it
- on land
- most have legs brought well under body
- smaller bipedal prob fast
Dromaeosauridae, may have had a slightly different life style
did dinos fly?
suggested that perhaps smaller forms like Microraptor, with its 4 wings, may have developed flight INDEPENDENT of birds
did dinos burrow?
- yes
- Oryctodromeus cubicularis ( “digging runner of the lair”) has been found in burrows in southwest Montana. Specimens that have been found include an adult and two juveniles
- dino burrows found in Cre rock in Aus (polar 110 ma) maybe burrow to keep warm
did dinos live in water?
semi - aquatic
(ichthyosaurs, mosasaurs and plesiosaurs are NOT dinosaurs!
Spinosaurus ate fish
1.Could the sail of Spinosaurus have been used as a heat regulator or as storage for fat? Why, or why not?
2.What else could the sail of Spinoceras have been used for other than the functions suggested in Question 1?
3.What kind of environment did Spinosaurus live in, and what did the animal eat?
4.List THREE pieces of evidence from its skeleton that the researchers used to determine the answer to Question 3.
5.How do the researchers explain the presence of so many large predators in the Kem Kem beds when there are so few large terrestrial plant eaters?
6.How is it possible to find Spinosaurus fossils in the Sahara Dessert today?
how to tell if dino was carnivore or herbivore?
Teeth (pointy= meat)
how did sauropods eat?
- ate all the time
- peg/spoon like teeth
- grind then gulped food
- had gastoliths
what is a gastrolith
in plant eating dino stomachs
- polished stone help digestion
what are possible hunting strategies carnivores
chase, wound and let die, coordinate in packs
did dromaeosaurid dinosaur (the group to which velociraptors belong) hunt in packs?
maybe , have trackways together but hard to tell
- group tracways found in E china
Allosaurus
- top pred lat Jur
- could reach 11m long
-leg t rex but better arms
what does the allosaurs brain look like
more crocodile less bird
- large olfactory bulb (smell)
- small cerebrum (evaluating, interpreting and processing data)
what was found in Cleveland-Lloyd Dinosaur Quarry in Utah?
79 dinos with 2/3 being allosaurs
- natural pred trap
- muddy watering hole trapped dinos, rotting dino attract allosaurs
- dino struggle to free themselves explain why dinos so mixed up
who is big Al
allosaurus live late Jur 145 ma
- nealy complet fossil found Wyoming in 1991
1.Who is “Big Al” and in what geological period did he live?
2.In what type of sedimentary environment was he preserved?
3.Who are Big Al’s closest living relatives?
4.How long did it take for an allosaur to grow to full size?
5.Were allosaur brains more like birds or alligators?
6.Other than brain shape, what also suggests that allosaur feeding behavior may have been similar to that of alligators?
7.What do paleontologists think caused Big Al’s death?
first and best place for evidence that some dinos may have been parental?
who discovered it?
W Montana in Egg mountain
- discovered by Jack Horner
What was found on egg mountain?
lots egg shells and some juveniles Maiasaura (caring mother lizard)
- nest closely packed and (less 7m apart) like seabird colony
- had 30-40 ostrich sized eggs in circular or spiral patterns
how did Maiasaura take care of there eggs
could babies walk right away?
use rotting vegitation to help incubate eggs
probably couldn’t walk right away
A different fossil depicts an adult surrounded by six young, suggesting these dinosaurs were living together as a family group at the time they died. This 160 million year old fossil demonstrates the oldest record of parental care in any reptile group.
This 120 million year old fossil shows an adult dinosaur in charge of 34 juveniles, in a sort of dinosaur nursery.
who published a paper that overturned that dinos where slow lumbering cretures
Bob Bakker
What does Posture/gate tell about if dinos where endotherms (warm-blooded) or ectotherms (cold blooded)
Ectotherms like lizards and crocodiles have a sprawling gate
endo like birds/mammals as well as most dinos had limbs directly under body
- association is a weak argument though
no direct link b/w posture and metabolism
What does lots of channels through bone indicate
what’s an exception
- lots blood vessels allow fast exchange Ca/phosphates in blood
crocs also have this
bone from diff part body can show diff microstructure
does O isotope ratio tell anything about metabolism?
expect mammals maintain temp so ratio same throughout skeleton
no, study living mammals/birds found ration O16:O18 can vary from core to extremities
what metabolism need more food?
can ecosystem support more endo or ecto top pred?
what’s the prob with using this approach on dinos?
endotherms
ectotherms
dino fossils hard to find
tells nothing about the prey dinos
what metabolism could sauropods have
what current animal is this similar to
gigantothermy
large so low surface to volume area and generated a lot of heat by moving
leatherback sea turtle
what are all the possible dino metabolisms?
- ectotherm, endotherm, gigantotherm, unknown dino metabolism
