History of the Hominoidea Flashcards
What are the hominoidea?
It is a superfamily including apes.
Name two features of the hominoidea
1) Loss of tail
2) Premaxilla overlaps maxilla
Where are early hominoids from?
1) Early Miocene (25-17mya)
2) Africa and West Asia predominately Rift Valley locales
3) Many volcanics so good dating
Describe Kamoyapithecus
1) Northern Kenya
2) 24-27 mya (Oligo-Miocene)
3) Not bilophodont (like hominoids)
Describe the features of proconsulids.
1) 2 premolars
2) Buonodont molars
3) Lingual cingulum
(NOTE: these three features above are primitive! Can be found in Ekembo heseloni).
They show dental diveristy:
Ekembo has small premolars and large lingual cingulum whereas Morotpithecus has large premolars and reduced lingual cingulum.
Name ten adaptations for suspension.
1) Very long forelimbs
2) Long clavicle
3) Globular humeral head
4) Redirected glenoid
5) Craniocaudally elongated scapula
6) Dorsally placed scapula
7) Broad sternum
8) Mobile hip joint
9) Broad femoral condyles (knee)
10) Robust hallux
Describe Ekembo
1) Complete tubular ectotympanic
2) No entepicondylar foramen in humerus
What is the fossil code of Ekembo heseloni? Describe some key features of this fossil.
KNM RU 2036
1) Complete tubular ectotympanic
2) No entepicondylar foramen
Describe the postcrania of stem hominoids
1) Loss of entepicondylar foramen
2) Partially spooled trochlea
3) Wide ulnar-carpal articulation
4) Forelimbs and hindlimbs equal length (Extant apes have longer forelimbs)
5) No tail
Hominoid ____ traits evolved prior to ________ traits.
Hominoid SKULL traits evolved prior to POSTCRANIAL traits
How can we tell in the fossil record if an animal had a tail? Because absence of evidence is not evidence of absence.
Animals with a tail have a fused vertebrae in the sacrum is straight
In animals without a tail the fused vertebrae in the sacrum is cone shaped (due to the sacrum curling under the body)
Describe the hominoids in the middle Miocene in terms of where they were and what they were doing.
1) Africa, Asia and Europe
2) Lower diversity and abundance of hominoids
3) Locomotion most likely varied:
quadrupedal, suspensory and semi-terrestrial
Describe a feature of Otavipithecus that is a synapomorphy of African apes.
Extensive frontal sinus
What is a hominid?
Apes
What is a hominin?
Human species
