Human Evolution 01 Flashcards
What were the most important extinction events in primate evolution and why?
Cretaceous-Paleogene: anatomically modern groups of mammals, global warming
Eocene-Oligocene (Grand Coupure): spread of grasses, seed plants, perissodactyla and apes; ice ages, deserts, climatic perturbations, salinity crisis, closure of thetis sea
Plesidapiformes
• Palaeocene - Eocene
• arboreal
• fruit, sap, insects, leaves
• dental similarities to adapidae (extinct primates), but lacked many primate characteristics
• stem primates or sister group of primates and dermoptera (Riesengleiter)?
Adapids
• Eocene
• arboreal, fruit & leaves, insects
• stem strepsirrhines (basal primates, e.g. lemurs)
• lack toothcombs (front teeth arranged for grooming) & toilet claw
• true postorbital bars
Omomyids
• Eocene
• arboreal, leaf & fruit, insects
• stem strepsirrhines
• large eyes = nocturnal
• grasping hands, nails instead of claws except:
• toilet claw
• bullae
Darwinius masillae
• mid eocene
• “Ida” private fossil
• no dental comb
• nails instead of claws
Anthropoids
Eosimias
• Eocene
• only teeth and mandible known
Catarrhines (Old World Monkeys and Apes)
Aegyptopithecus
• Oligocene (33 Ma)
• lower molars with great-ape-like cusp patterns (stripes)
• brain smaller than lemurs
• strong vision
Proconsulids
• Miocene (23-14 Ma)
• arboreal, frugivorous
• pronograde (walking with body approximately horizontal, on all four?)
• before monkey-ape split?
• lacks tail
• long & flexible lumbar spines
Dryopithecinae
Dryopithecus
Dryopithecus fontani
Pierolapithecus catalaunicus
• 13-12.5 Ma
• arboreal great ape, not suspensory (hanging from trees behaviour)
• flat face
• scapula on back rather than on sides
• large flat thorax
Danuvius guggenmosi
(Dryopithecinae)
• body proportions similar to bonobos: broad thorax, long & flexible lumbar spine, extended hips and knees (as in bipeds: for weight bearing)
• forelimbs and hindlimbs equally used
• long, curved fallanges
• lacked robust finger bones => suspensory behavior, bipedalism?
Oreopithecus
(unclear affinities)
9-7 Ma, ca. 32 kg
• arboreal brachiator in swampy habitat/ biped?
• leaf eating
• short pelvis (biped?)
• lumbar lordosis? (vertebrae similar to bipeds)
• unique foot morphology => bipedal support
• hip bone suggests bipedalism
• peculiar features due to island isolation
Sivapithecus
Ramapithecus (14-8 Ma) is female to Sivapithecus, (upright posture, hands free for tooluse?) has small canines and flat molars, as well as thought to have parabolic dental arcade => later V-shaped dentition
• rather closely related to Orang-Utan
Gigantopithecus
• 2 Ma to 300 ka
• only teeth (found in Hongkong “Dragonteeth”)
• no postcranial (every bone exept skull) bones so far, estimated 200-300 kg
• enamel proteome => proteins survive longer as DNA, but highly degraded
=> result, probably derived from Pongo (Orang-Utans)
Sahelanthropus tchadensis
Upper Miocene (~7 Ma)
• might be earliest hominin
• foramen magnum in more central position
• angle of orbita => forward facing eyes
• oval femur (triangular in humans) => affinity with chimps, not as humanlike as suggested
=> but: thicker bones laterally like humans
• long, curved ulna (arboreal behavior)
• deformed skull?
Orrorin (“Original Man”)
• bidirectional thickening of femoral bone (unequally distributed) rather than equally distributed as in chimps
• femur with large head and long neck, shape of femur similar to Miocene apes and hominins
• tickly enamelled, small, squared molars
