Lab Test 2 Flashcards
Anterior
Towards the nose of organism
Posterior
Opposite direction of anterior - towards the back end
Ventral
Towards the belly of the organism
Dorsal
Towards the back of the organism (eg. dorsal fin), opposite of ventral
Cranial
Towards the head (same as anterior in dinos)
Caudal
Towards the tail (same as posterior in dinos)
Proximal
Towards here the appendage joins the body
Distal
Towards the point further from the point of attachment to the body
Lateral
Towards the left or right side of the organism
Medial
Opposite of lateral- towards the midline of the organism
Label the skull openings on the dorsal view of the Eocaptorhinus, what kind of skull did it have?
Orbit, anapsid
Label the letters on the Tyrannosaurus Rex skull
A - lower temporal fenestra
B - upper temporal fenestra
C - orbit
D - antorbital fenestra
E - nasal opening
F - mandibular fenestra
What are the lines pointing to on the skull of the American Alligator? What are the characteristics that (1) classify it as a diapsid reptile, and (2) classify it as an archosaur? Where is it’s antorbital fenestrae?
Two temporal fenestra (1)
(2) socketed teeth
Antorbital fenestrae covered in bone
Label the Allosaurus vertebra
A - zygapophyses
B - neural canal
C - transverse process
D - centrum
E - neural arch
F - neural spine
Definitions/descriptions of :
Vertebra
Centrum
Neural arch
Neural canal
Neural spine
Zygapophyses
Transverse process
Spinal column is divided up into bone segments, each of which is called a VERTEBRA. Vertebra is made up of spool-spayed centrum and a neural arch. Between the centrum and the neural arch is the tubular passage called the neural canal, and holds the nerves of the spinal cord. The neural arch typically has a blade-like upward extension called a neural spine. Vertebrae may also have articular process (aka zygapophyses), which are paired projections on the anterior and posterior ends of each vertebrae that link (articulate) with the adjoining vertebrae. Transverse process stick out on the sides of the vertebrae and Steve as attachment sites for muscles or ligaments.
Definitions/descriptions of :
Vertebra
Centrum
Neural arch
Neural canal
Neural spine
Zygapophyses
Transverse process
Spinal column is divided up into bone segments, each of which is called a VERTEBRA. Vertebra is made up of spool-spayed CENTRUM and a NEURAL ARCH. Between the centrum and the neural arch is the tubular passage called the NEURAL CANAL, and holds the nerves of the spinal cord. The neural arch typically has a blade-like upward extension called a NEURAL SPINE. Vertebrae may also have articular process (aka ZYGAPOPHYSES), which are paired projections on the anterior and posterior ends of each vertebrae that link (articulate) with the adjoining vertebrae. TRANSVERSE PROCESS stick out on the sides of the vertebrae and Steve as attachment sites for muscles or ligaments.
Label the vertebrae
A - neural canal
B - centrum
C - neural arch
Match the proximal and distal end of the Allosaurus terminal phalanx of the front foot with the left and right side of the drawing
Proximal on left
Distal on right
Label the allosaurus dentary
A - tooth sockets
B - serrations
C - mobile joint
D - mandibular fenestra
Label the shark tooth and directions
A - crown
B - root
C - serrations
(1) - distal
(2) - proximal
Label the tyrannosaurus tooth and directions
A - serrations
B - crown
C - root
(1) distal
(2) proximal
Dentition
The development and arrangement of animals teeth
Temporalis muscles
Responsible for pulling the mandible up and back towards the skull
Homodont dentition
All teeth are generally the same shape but vary in size, seen in carnivorous dinosaurs
Wear surface
Flattened area in herbivore teeth as a result of tough vegetation and lots of grinding when eating.
Heterodont dentition
Nipping teeth in the front and grinding teeth in the back (front can also be a biting pad or beak) (some lineage cay have simple peg-like teeth throughout the mouth without grinding teeth in the back)
Label the tooth. Is it a carnivore or herbivore? What was its diet?
A - crown
B - root
Herbivore - stegosaur tooth
Little to no wear on tooth, very soft vegetation in diet
If a tooth has anterior and posterior serrations present, would it belong to a carnivore or herbivore? What would the specific diet be?
Carnivore - carcharadontosaur tooth
Ate flesh/muscle with serrations
Label the enamel and crown of the cross sectional view of tooth. Would it belong to a herbivore or carnivore? What is the specific diet?
A - enamel
B - crown
Carnivore eating fish - circular cross-section
Spinosaurus tooth
Label the crown and tooth of the tooth. Would it belong to a herbivore or carnivore? What is the specific diet?
A - crown
B - root
Herbivore eating tough vegetation (wear surface visible on tooth)
Triceratops tooth
A tooth with flat wear surface on side of tooth. Would it belong to a herbivore or carnivore? What is the specific diet?
Herbivore eating vegetation (less wear = softer vegetation, more wear = tougher vegetation)
Tooth with very large flat wear surface. Teeth are pressed closely together with no spaces between them. Would it belong to a herbivore or carnivore? What is the specific diet?
Herbivore eating very tough vegetation from very large wear surface
Some wear on distal surface of tooth. Would it belong to a herbivore or carnivore? What is the specific diet?
Herbivore, moderately tough vegetation from some wear
Label the skull of the brachiosaurus. Was it a herbivore or carnivore, why?
A - temporal fenestra
B - orbit
C - nares
D - antorbital fenestra
Herbivore because teeth are simple and peg-like with no serrations
What was the function of the spaces between the teeth? What do the shape and arrangement of teeth tell you about Brachiosaurus’ feeding strategy?
Spaces are for branches to pass through the mouth as the teeth strip off its leaves. There are no wear surfaces on the teeth, so they likely ate softer vegetation and didn’t process food in the mouth.
What can you tell about a dino with teeth in a series with serrations along the edges of each tooth
Meat eating dinos
What is the highlighted part? What is its function?
Sagittarius crest for attachment of strong jaw muscles, creating a stronger bite force
When looking at orbits, what does it mean when eyes face forward vs pointing to the side
Eyes forward = allowing to see in 3D
Eyes to side = not in 3D
Mobile zone and large fenestra on mandible means…
Allowed the mandible to flex and move while the dino is biting to move around any bones and bite through flesh and muscle
Little to no wear surface on a herbivore tooth and large gut shows what about processing food?
They must have eaten vegetation that does not require much mechanical processing. The large gut may have acted as a large fermentation chamber
Large orbits and eyes forwards means what?
Large orbits relative to body and skull shows that it relied heavily on sight and can see in 3D
Looking at the Velociraptor, did they engage in high-speed chases to capture prey?
Skull is very lightly arranged and a streamlines shape (so is the body)
Does the nanosaurus have homodont or heterodont dentition? Herbivore or carnivore? How do the tooth in the anterior of the mouth differ from the tooth in the posterior of the mouth? What is the purpose of each type of tooth?
Heterodont, herbivore
The anterior tooth are widely spaces and do not have wear surfaces, they are used for stripping leaves off branches. The posterior teeth are very tightly packed into a single tooth called a “dental battery”. That have a large wear surface for grinding tough vegetation
Diastema definition and function
= gap between the front and back teeth
It allows food to be pushed into or out of the wheels with the tongue during eating
A triceratops has a flat wear surface on teeth. Is the grinding of the food done in the mouth? How much grinding? How do you know?
Teeth have flat wear surfaces, indicating grinding of vegetation in the mouth
What is the purpose of having no teeth in the anterior of the mouth in a herbivore?
No teeth in anterior of triceratops mouth, instead there is a nipping pad and beak used to grasp vegetation and pull it into the mouth, where it is ground by the posterior teeth
Would a herbivore have forward or lateral facing orbits?
Lateral to see more vegetation in their surrounding, no need to see in 3D for catching prey
Dental battery indicates grab and gulp or grinding strategy?
Grinding
What are gastroliths most likely made up of?
Stomach acids would dissolve minerals like calcite or halite, so gastroliths must be made up of very resistant minerals like quartz
Gastroliths are linked to what feeding strategy?
Likely grab and gulp as the gastroliths provide mechanical processing after the food is swallowed
Mechanical function of ornamentation definition
The structure may be used in dinosaurs basic functions, such as feeding, locomotion, insulation, or communication
Ornamentation for defence definition
Some structures may be used in active defence (counterattacking a predator) or passive defence (acting as a “shield” from predator bites, or simply repelling predators)
Sexual competition from ornamentation definition
Ornamentation may be used to attract mates (like a peacocks tail) or repel/fight rivals for mates (like a bighorn sheep’s horns)
Ornamentation for species recognition definition
Unique structures may allow individuals to recognize other members of the same species
Pachycephalosaurus has spikes, dome, and scutes on the skull. What are the possible functions?
So much ornamentation that the antorbital and temporal fenestra are covered
Function: dome for head-butting other pachycephalosaurs in intra-species competition, spikes and scutes for display or defence against predators
Mechanical, defence, sexual
Parasaurolophus ornamentation and function
Crest on skull that extends from tup of nose, past posterior end of skull
Function: display or communication
Mechanical (communication), sexual
Protoceratops ornamentation and function
Frill on skull has simple (smooth) margin, with two large fenestra (seen in skeleton)
Function: display or defence
Mechanical (skin warmth), passive defence (shield), sexual
Stegosaurus ornamentation and function
Plates along spine are large (larger than head) and from two alternating rows on either side of spine. Groves on plates indicating vascularity. Two spikes on distal end of tail, pointing laterally outwards, scutes cover underside of neck
Function: scutes and spikes for defence, or plates for thermoregulation or display
Mechanical (plates thermal), defence (passive - plates and scute, active - tail spike), sexual (plates)
Styracosaurus ornamentation and function
One nasal horn, spike along the margin of the frill. Frill has 2 fenestra visible in skeleton
Function: horns for defence, or frills for defence and display
Mechanical (frill insulation), defence (protection with horns), sexual
Triceratops ornamentation and function
Two postorbital horns and one nasal horn. Frill and nasal horn have grooves indicating vascularity
Function: horns for display, frill for defence or display
Mechanical (frill thermal), defence (horns- passive), sexual (frill)
What can be said about the robustness of frills in triceratops, styracosaurus, and protoceratops
Triceratops has a robust frill, but the other two have large fenestrae in their frills, which may have only been covered by skin and other soft tissues.
How do you tell the difference between male and female protoceratops (4 points)
Left (a) female
Right (b) male
1) males have relatively short skull from a lateral view
2) males frill rises from the skull at a greater (more vertical) angle than in the female
3) the frill is more rounded in males than in females
4) the frill in males has a smaller fenestra and thicker margin around the fenestra than the female skull
Describe the horn and frill morphology of each life stage of a triceratops
(A) Baby:
- frill: relatively small compared to skull size, some epoccipitals
- post-orbital horns: very small
- nasal horn: very small
(B) small juvenile:
- frill: roughly same length as rest of skull. Pronounced epoccipitals
- post-orbital horns: relatively short, curved towards the posterior
- nasal horn: small
(C) Large juvenile:
- frill: roughly same length as rest of skull. Pronounced epoccipitals
- post-orbital horns: long, about as long as front-to-back length of the skull. Curved towards posterior
- nasal horn: small
(D) Subadult:
- frill: appears to be largest here. Epoccipitals less pronounced, margin more smooth
- post-orbital horns: roughly the same length as large juvenile. Straight.
- nasal horn: small
(E) adult:
- frill: epoccipitals not visible. Frill appears to be slightly smaller, relatively.
- post-orbital horns: shorter than subadult, curved anteriorly
- nasal horn: relative to skull size, this is where the nasal horn is longest
Mechanical function of triceratops based on the ontology
If the frill is used for heat retention/dispersion, its function is to increase surface area of the animal. Small juveniles may have relatively small frills because smaller animals already have a high surface area to volume ratio. They may need a bigger frill as they grow and the ratio decreases
Defence of triceratops based on the ontology
Baby triceratops doesn’t have much defence, in terms of frill and horn size, but maybe they lived in family groups and the babies were protected by the better-equipped adults
Sexual competition of triceratops based on the ontology
Changes in frill and horn morphology during ontogeny are a way that triceratops can judge the age of others, and thus select potential mates. The horn and frill are largest (and presumably most impressive to other triceratops) at the young adult stage, which is typically reproductive age.
Species recognition in triceratops based on the ontology
There are major changes in frill and horns during ontogeny, which would complicate species recognition
What hypothesis of function of ornamentation support in this photo of two triceratops in full horn locking posititon
It supports sexual competition hypothesis. We know that triceratops could have, and did, have intraspecies “fights”
What hypothesis of function of ornamentation support in this photo of ceratopsian dinosaurs that lived in large herds in highly social circumstances
Defence: even though baby triceratops was unable to defend itself, it lived with a family group that could have defended it
Sexual competition: ceratopsian dinosaurs would have had to recognize who in the herd was of breeding age, and compete with others in the herd for mates
Two purposes of the hardosaur crest
1) visual display: size, shape, colour of crest may have conveyed information about species, sex, age, etc.
2) vocal resonator: the crest may have been used as an instrument to produce and amplify sound, particularly for long-distance communication
What are the variable in this equation:
F=n(v/(2L))
F = frequency in Hz
N = resonance mode (will be provided)
V = speed of sound, approximately 340 m/s
L = length of tube through which the sound is travelling, in m
Would parasaurolophus been able to hear the sounds that were produced though the nasal crest?
Yes, if they produced the sound to communicate with each other, then they would’ve been able to hear it.
Would a juvenile parasaurolophus vocalize at a higher or lower frequencies than an adult?
Higher - smaller horn = higher frequency
Two morphs of stegosaurus plates: tall and wide morph. What is the best hypothesis for the two plate morphs?
Sexual dimorphism: males had one plate morph, and females had the other
Label the ilium of the allosaurus. Is it a left or right ilium?
(1) - dorsal
(2) - anterior
(3) - ventral
(4) - posterior
A - ilium
B - pubis
C - acetabulum
D - ischium
Label the caudal vertebra of allosaurus
A - neural arch
B - neural spine
C - post-zygapophysis
D - centrum
E - transverse process
F - pre-zygapophysis
What part of the human foot does the proximal end of the small theropod footprints correspond to?
The ball of the human foot
How many toes did a velociraptor walk on?
Two
What would not have been preserved in a fossil feather?
Original colour
