Dinosaur Palaeobiology

Question 1

how do veloceraptors differ in reality in comparison to how they are portrayed in movies etc

Answer 1

• actually thought to be feathered
• relatively smaller = 1.8 metres
• likely to have been able to glide
• evidence they hunted in packs

Question 2

what are some of the problems associated with studying dead or extinct species

Answer 2

• cant directly observe them
• skeletal morphology can be misleading due to imperfect correlations with ecology and soft tissue structures are not visable alot of the time e.g. the fatty humps of the camel
• soft tissue does not fossilise well

Question 3

outline the phylogeny of major dinosaur groupings including theropods, sauropods, thyreophorans, ornithopods and ceratopsians

Answer 3

theropods = mostly carnivorous dinosaurs
sauropods= big things with long necks
theyreophorans = armoured dinosaurs
ornithopods= duck billed dinosaurs
ceratopsians = horned dinosaurs with frills

Question 4

how have fossil records of hard tissues give us insights into dinosaur ornamentation

Answer 4

ornaments made of hard, readily fossilised parts tend to fossilise well e.g. plates and spikes on the stegosaurus (thagomizers)

Question 5

how have fossilisation of soft tissues provided us with information about dinosaur ornamentation

Answer 5

• soft tissue also fossilises but rarely enabling us to identify structures which are not deducible from the skeletal remains alone

= Bell et al 2014= found using xray images a less dense area at the back of the head making up a cox cone on the edmontosaurus regalis males
= thought to be a sexually selected trait for making providing us with an idea of behaviour

= Vinther et al 2016 = found fossalised skin of a psittacosaurus and was able to reconstruct the colour patterns and cells which still contained the pigment cells making it lighter / darker

Question 6

outline how fossil records of feathers help with our understanding of the origin of birds

Answer 6

they fossilise well as they are harder than soft tissue
- downy feathers probably existed in most theropods (group including birds)
- more typical feather structures evolved at least twice
- flight feathers were likely present in a few groups of theropods closely related to birds
= one case a record showed a transition from downy–> typical feathers as the animal grows

Question 7

what does fossil evidence suggest about reproduction

Answer 7

suggests most or all dinos laid eggs and many fossilised eggs have been found in a range of shapes, sizes and orientations
= able to ID spp sometimes from them from mini skeletons within more developed eggs (Reisz et al 2005) or from egg structures

Question 8

what can the egg structure from fossilised eggs tell us

Answer 8

microscopic structure of fossilised egg shells is preserved showing details of mineral comp and crystal structure which closely mirror living bird spp

e.g. Troodontid and emu eggs

Question 9

how can looking at egg structure provide information about the types of nests dinosaurs built

Answer 9

shells contain pores to enable gas exchange and water exchange with the enviro
- size and shape of pores vary
- closed nests e.g. eggs which are buried, the humidity is higher and respiration is reduces so have larger pores
- open nests e.g. on top of twigs etc, humidity is lower and more contact with air so egg shells have small pores

Question 10

how can fossils provide information about diets of dinos

Answer 10

• look at the location of bones in the body cavities
• look at marks left behinde on fossils e.g. claws to identify what preyed on what = info on hunting stratergy etc
• dentition can tell us what they eat = relies soleyon analogy with living animals

Question 11

anoles have evolved such diverse morphologies, but have these similar morphologies evolved through the same genetic changes at different species or does it differ

Answer 11

• early days in the analysis of genetic of their adaptive radiation
• studies of developing embryos show differences in limb morphology during earliest stages of limb development
• allos ID egnes which determine limb growth and differentiation
• comparing DNA sequences of these genes amoung different spp should allow researchers to determine if similar changes in gene expression are involved in the convergent evolution of limb morphology

Question 12

How else in the Anole genome being used other than to look at the convergent evolution of limb morphologies

Answer 12

• provided resource from which to develop a large number of genetic markers used to infer evolutionary relationships among species
• allows provision of hypothesis regarding relationships amoung spp which can be used to trace evolution of genes, phenotypes, behaviour and ecology