The Living Primates/ primate evolution Flashcards
Why do we study non human primates?
- understand physical and behavioural diversity
- living models for interpreting hominid fossil remains
- conservation
What are the characteristics of chordata (vertebrate)
- has spinal cord, covered by vertebrae
- bilateral symmetry (left side same as right)
- share same skeletal design (arms, legs etc)
What are some characteristics of mammalian (mammals)
- 200 mya was first
- viviparous (births live offspring)
- many are placental (famales connected to fetus through placenta) (limited offspring)
- females possess mammary glands which provide food for offspring
- homoiotherms: regulate body temperature (fur, fluctuation of blood cell size)
- dentition (2 sets of teeth, different types of teeth)
- skeletal structure ( limbs tucked under body)
What is the dental formula for mammals
2 incisors
1 canine
2 premolars
3 molars
What are primate characteristics
- hands/feet (opposable thumbs, nails no claws (most), lots of nerves in tips of fingers)
- forward facing eyes/ stereoscopic vision
- long period of infant dependency and learning
- mainly tropical, arboreal, vegetarian
- found 30 degrees above or below equator
Describe prosimians
- found in Asia, Africa, Madagascar
- small medium sized
- nocturnal (mostly)
- vertical climbing and leaping
- quadrupedal
What’s the difference between old world and new world monkeys
Old world nostrils are downward pointing, new world are broad and flat. Old world have 2 premolars new world have 3. New world all live in trees, old world is trees and ground
Describe hominoids
- old world apes and humans
- absence of tails
- dentition
- differences in skeletal structure and shape
What is “the fossil record”
- “bone that have turned to stone”
- impressions of ancient life forms (footprints, endocasts)
Whats a holotype?
The best or most complete form of a fossil; standard for other fossil recoveries are compared
What is an analogy?
Similarities organisms share due to similar adaptation to similar selective pressure (convergent evolution)
What is homology
Similarities organisms share because of common ancestry; taxonomic significance
What is a primitive trait
Trait that has not changed from ancestral state
What is a derived trait
Trait that has changed from ancestral state
Describe the Paleocene?
- 65-53 mya
- primate origins : plesiadapiformes
Describe the Eocene
- 53-37 mya
- abundant fossil evidence for early primates (prosimians and possible anthropoids)
- fossils recovered in NA and Europe (closer to the equator at this time)
Describe oligocene
- 37-22.5 mya
- definite anthropoid proliferation (unambiguous remains 36 mya)
Describe the Miocene
- 22.5-5 mya
- abundance of fossil apes in old world; hominin split from apes in africa
Describe the Pliocene
- 5-1.8 mya
- first hominin fossils, first artifacts
Describe the Pleistocene
- 1.8mya-10000 ya
- hominin migration outside of Africa; appearance of modern humans, origins of socially complex societies
Describe the Holocene
- 10000 ya- to present
- spread of agriculture, rise of large scale civilizations
What is Pangea
Movement of continental land masses - implications for climate and evolution of living primates
What did the continents separate?
End of the Mesozoic beginning of Cenozoic about 65 million years ago (early palaeocene)
What are the two main super families of the of the Eocene primates?
- Omomyoidea (Eocene tarsiers)
- adapoidea (Eocene lemurs)
Describe Oliocene primates
- first anthropoids
- temperature cooled -less rain forest
- anthropoids became prominent and completed with prosimians (nocturnal)
What were the major adaptations that made anthropoids distinct?
- change in diet - larger stronger teeth, reinforced skulls and jaw bones for seeds instead of soft fruit
What are Paleoanthropologists still looking for?
- common ancestor of monkeys apes and humans
- when platyrrhines and catarrhines diverged
- when catarrhines branched into owm and hominoids
- looking in the oligocene
What is the datum depression in Egypt?
Fossils layer created by ancient rain forests, lots of anthropoid and prosimians fossils
What is the Miocene characterized by?
- emergence of fossil apes and great morphological variation
- by late Miocene many apr species went extinct and monkeys dominated
Describe proconsul
- mixture of ape and monkey like arributes
- relatively large (33-110 lbs)
- fruit eater
- limb proportion similar to quadruped monkey
- no tale
Describe Kenyapithicus
-earliest definite hominoids fossil
Describe sivapithecus
- from Europe and Asia
- ancestor to modern orangutan
Describe gigantopithecus
-Largest known primate (10ft 600 lbs)
Became extinct 250000 ya
Describe dryopithecus
- great ape
- European
- has y-5 molars
- capable of suspensory locomotion