Vertebrates Flashcards
are of immense importance in aquatic and terrestrial ecosystems from the Ordovician onwards.
They are commonly present as predators and scavengers, becoming almost ubiquitous in modern faunas.
Vertebrates
the reinforced rod that runs down the animal’s back, is what makes it unique. In vertebrates, this often mineralizes to create a backbone that encircles a lengthy nerve sheaf.
chordate notochord
In all skeletonized vertebrates the substance employed is calcium phosphate (CaP04), combined with an organic material used as a
template
The first vertebrates are Cambrian in age and include conodont teeth and rare fish. A close ancestor of vertebrates is the Burgess Shale animal
Pilzaia
Vertebrates include fish, amphibians, reptiles, dinosaurs, mammals, and birds.
The earliest vertebrates were ____, and all of them were marine
fish
Most of these early fish lacked jaws.
Jaws evolved in the Silurian and this group, sometimes known as
gnathostomes
Primitive gnathostomes
cartilaginous
bony fish
several extinct groups fish
placoderms
acanthodians
It allows them to extend their jaws beyond their resting position, significantly increasing their reach and ability to capture prey or manipulate objects.
Jaw Protrusion
are tetrapods that lay eggs in water.
ancestral group to all of the other tetrapods, including reptiles, dinosaurs, and mammals, as well as birds.
AMPHIBIANS
The most likely ancestors of amphibians, and all other tetrapods, are a group of extinct lobefin fish known as
rhipidistians
Reptiles evolved from amphibians during the Carboniferous.
Their key innovation is the ability to lay eggs on land.
These amniotic eggs are a life support system for the embryo away from water
Amniotes
One possible early amniote is ____________, a small tetrapod found in a Carboniferous volcanic lake deposit from the Midland Valley of Scotland.
Westlothiana
The earliest well-known reptile is called ___________ and is found in the hollow tree stumps of a Carboniferous fossil forest in eastern Canada.
Hylonomus
Carboniferous origin, this is the primitive group of reptiles; Never very abundant or diverse. Greatest diversity of form in the Permian, Greatest success after the evolution of the shell in the Triassic
Anapsids
Carboniferous; Pelycosaurs in the early Permian, therapsids in the late Permian, True mammals in the Palaeocene
Synapsids
Carboniferous; Archosaurs, marine and flying reptiles in the Triassic. Dinosaurs in the Jurassic. Birds in the Palaeocene
Diapsids
from South Africa.
small, active insectivores of moderate size, with skulls typically around 5 cm long.
Permian Millerettids
lived in moderate to high southern latitudes.
were omnivores or herbivores.
Late Permian and Triassic Procolophonids
found in the northern hemisphere.
could reach 2-3m in length.
heavily build herbivores.
Late Permian Pareiasaurs
The first radiation was of the group known as
pelycosaurs.
the best-known pelycosaur.
Dimetrodon
radiated widely in the late Permian; shorter and more squat than the pelycosaurs.
Therapsids
common in the Triassic; include the species Thrinaxodon, which shows evidence of having had whiskers.
Cynodonts
suckle their young in pouches; found in South America and Australasia.
Marsupials
retain their young for longer inside the body; found in Asia, Europe, and N.A.
Placental mammals
lay eggs; found only in Australasia
Monotremes
humans, lemurs, monkeys, and apes, as well as our direct ancestors. Traced back to the late Cretaceous, radiated early Cenozoic.
Primates
Around 6 million years ago
grassland-dwelling apes were the
australopithecines.
oldest well-preserved skeletons; dated 3.2 million years ago.
evolved in two different ways:
1. towards heavily built vegetarians with small brains.
2. towards more lightly built omnivores who used simple tools
Australopithecus Afarensis
the more robust lineage
- identified in Africa.
- groups of these large vegetarians
likely coexisted with our direct ancestors.
Paranthropus
