Midterm 2 Part 2 Flashcards
What is the primary evidence of herding in some dinosaurs?
Large bonebeds of a single species
What is the difference between continental drift and plate tectonics?
Continental drift is when the continents are all on separate plates, plate tectonics define plate boundaries a little differently (include parts of the ocean and sometimes splits continents)
What drives plate tectonics?
Convection and gravity
Cold, dense things go down and gravity pulls them under
What is evidence of plate tectonics?
Seafloor spreading
Is the mantle liquid or solid?
Solid, but brittle
The large feathery wings found on many theropod arms primarily functioned…
as display
In most vertebrates, skulls are the primary part of the skeleton used in classification. Why then are the vertebrae used for this purpose in sauropods?
Sauropod skulls are fragile and rarely preserved
What evidence in the leg bone structure of a dinosaur would suggest that it is a fast runner?
Long metatarsals, long tibia, short femur
What is/are the primary diagnostic character(s) of Thyreophora?
Large number of dermal ossicles
In addition to the pelvis, another diagnostic character of ornithischian dinosaurs is/are?
Ossified tendons along the back
The club at the end of the ankylosaurid tail consists of enlarged…
Dermal ossicles
What is the evidence of cheeks in ornithischians?
Ridges along the maxilla and dentary
WHy is it important to understand the geology/rocks of a dig site?
They provide information about the environment in which the animal lived and died
To collect vertebrate fossils on state and federal lands, paleontologists must secure a permit. The purpose of the permit is to…
Protect fossils from poaching
Digital “preparation” of fossils while they are still in the rock has the advantage of
Minimizing damage to the fossils while still providing a 3D image (not necessarily cheaper or faster)
A lumper is a paleontologist (biologist) that
Places two or more species into a single species
Pachycephalosaurs and Ceratopsians are grouped in a clade diagnosed by which of the following characters?
A ridge or crest at the back of the skull
Evidence that pachycephalosaurs butted heads is given by…
Pathological pits on the skull tops (having thick skulls alone doesn’t prove that they butted heads).
Why are ceratopsians found only in North America and Asia?
The clade existed when there were no links between North and South America
In addition to serving as jaw muscle attachments, the frills of ceratopsians likely served for…
Display and defense
Do ornithischians have cheeks?
Yes
Do saurischians have teeth?
No
In which group of dinosaurs is it common to find the skull because it’s so big and massive?
Marginocephalians
What causes ceratopsians to be quadrupedal?
The weight of their skull
True or False: Ceratopsians first evolved to be bipedal?
True
When we see evidence of bone damage that has not healed, what does that tell us?
That the dinosaur died shortly after receiving the damage or THAT is what killed the dinosaur. It could also tell us what kind of dinosaurs were chewing on bones after the dinosaur died.
What are the evolutionary novelties of neornithischians?
Don’t have an anteorbital fenestra, huge numbers of stacked teeth called dental batteries, hair-like feathers, little bone in the eye called palpebral
Which group of dinosaurs had fancy thumbs and grasped things with their pinky finger?
Styracosterna
A new find in Russia provides evidence that even ornithischians had feathers. To which clade of ornithiscian dinosaurs does this new find belong?
Ornithopoda
Self-sharpening teeth are found in which clade of dinosaurs?
Ornithopoda
Which group of ornithopods is characterized by crests developed from nasal chambers?
Lambiosaurinae
What is dental battery?
Stacks of teeth to grind vegetation
What does ossify mean?
To become bone
Evolutionary novelties of ornithischian dinosaurs
Palpebral bone, Predentary bone, tendons along the vertebrae ossify, pelvis has a posterior rod and anterior expansion
What does the predentary bone do?
Joins the left and right mandibles together
What groups of dinosaurs have rocks in their stomachs to help grind vegetation?
Basal ornithischians and thyreophorans (mainly herbivores)
What do ossifed tendons do for the dinosaur?
They provide stability, don’t limit mobility
Almost all ornithischians lose their anteorbital fenestra, what happens to it?
It fills in with bone
In Thyreophoran dinosaurs, what is the purpose of the gap between the front and back teeth?
Allows their tongue to snake out and grab food to bring to the back (where it’s grinded)
What would happen if the back teeth of a Thyreophoran wore down?
It would die
What does heterodontisauridae mean?
Different teeth
What are the bumps in an osteoderm?
Bone, covered in a fingernail-like material
What is the purpose of chevrons?
They protect the aorta
In Stegosauridae: Which came first, the spikes or the plates? Which was more primitive?
Spikes are primitive
True or false: The plates of Stegosauridae are connected to the bone
False, they’re just sitting on the skin
What is a browser?
They’re picky eaters, pick/look for individual things
What is a grazer?
Eat just about anything
What happened to the anteorbital fenestra of a stegosaurus?
Turned into a fossa
What is the purpose of Stegosaurus plates according to Brooks?
Protection, possibly display. Doubts they’re for regulation (but it’s possible they do both)
Which dinosaur group has jaws that shut like scisssors? Which go up and down normally?
Theropod like scissors
Sauropod go straight up and down
Ontogeny
The study of the development of an organism (from embryo/birth to adulthood)
Why do skulls fall off sauropod skeletons after death?
Because the vertebrae are weak and they’re not fused on very well.
Which type of dinosaur moves like a vacuum (moves forward a little, sweeps head in an arc, then moves forward again)
Sauropods
How many vertebrae do sauropods have?
Up to like 25, or maybe more
Did prosauropods walk on 2 legs or 4?
2
Did sauropods walk on 2 legs or 4?
4
What does ornithomimus mean?
Bird mimic
What changes happened to T-Rex as it got older that required it to change its hunting habits?
Started quick and agile as juvenile, but got huge head and little arms
Death pose
Head thrown back towards the neck
What were the wings of ornithomimus for?
To attract mates, display
What are the fenestra in jaws for?
Muscle attachments. The bigger the fenestra, the stronger the jaw
Pneumatic
Bones filled with air
Pneumatic bones occur in which clade of dinosaurs?
Saurischia
What is the original function of feathers?
Insulation
The diet of non-bird theropods is…
Primarily carnivory along with herbivory and omnivory
What is green bone?
Flexible bone
What is the furcula?
Two fused clavicles
What dinosaur clade gives a little hop to get off the ground?
Theropods
True or False: Ornithischians have air-filled vertebrae?
False
Tetrapod
terrestrial vertebrate
Theropod
Beast footed
Digitigrade
Dinosaurs walked on toes
Who came up with continental drift?
Alfred Wegner - German
What time period of geology is left in ocean floors?
Cretaceous, veryl ittle left of Jurassic
Basalt rocks
Dark brown or black like in idaho
Why does continental crust rarely sink down, when oceanic crust sinks all the time?
Because continental crust is much lighter than oceanic crust
What may cause a tectonic plate to be pulled down faster?
The size. The larger the plate, the more gravity can influence it
Which clade of dinosaurs do theropods belong to?
Saurischia
