EARTH 148 Midterm

Species

genera, family, order, class, phyla, kingdom

paraphyletic

artificial group; they include a common ancestor but exclude some of its descendants

ex. fish

Homology

fundemental similarities as a result of commono ancestry

Phylogeny

history of life

monophyletic

groups descended from a common ancestor + all living descendants of that common ancestor

Deuterostomes (Cambrian)

NODE

Has blastopore; anus forms first

Hemichordates (Cambrian)

cilliated phayngeal gill slits

Chordates (Cambrian)

NODE

notochord

ciliated pharyngeal slits

notochord

flexible, tough rod that is skeletal support for embryos of all chordates

urochordate (Cambrian)

sessile

bag-shaped

loses notochord in adult stage

Cephalochordates (Cambrian)

anteriro tentacles

dorsal hollow nerve chord (formed by neural crest) + notochord

Vertebrates (Cambrian)

NODE

skull

dorsal hollow nerve chord (formed by neural crest)

Dexiothetism

theory that echinoderms & chordates the same as hemichordates turned 90°

Paedomorphosis/Juvenile Adult Theory

attainment of sexual maturity during otherwise juvenile state of development

Modern classification scheme

amniotes

• reptiles

  • turtles

    • diapsids

      • lepidosaurs

      • archosaurs

        • crocodiles

        • birds

• synapsids

Reptile

most recent common ancestor of turtles, birds, and all descendants

Hagfish (Carboniferous)

slime “eels”

jawless

Lamprey (Devonian)

horny keratinized teeth

Ostracoderms (Ordovician)

shell skin

not monophyletic

Heterostracans (Silurian)

1 opening on each side of armored head

Osteostracans (Silurian)

scaled pectoral fins

paired appendages

Anaspids

downward bent tail

paired appendages

Gnathostomes (Silurian)

NODE

jawed

spiral intenstine

trabeculae

paired appendages

Trabeculae

paired, anterior components in the formation of embryonic baincase

Chondrichthyans (Devonian)

NODE

cartilagenous tooth-like placoid scales

internal fertilization via male calspers

Placoderms (Devonian)

dermal armor

no true teeth; sharpened dermal bone plates

neurocranium

Osteichthyes (Silurian)

NODE

bony fish

lungs/swimbladder form from gut

terminal mouth

neurocranium

Acanthodian (Silurian)

spiny shark

terminal mouth

neurocranium

not monophyletic

Actinopterygii (Devonian)

NODE

Ganoid scales

Acrodin caps on teeth

Polypterus (Devonian)

Actinopterygiian

swimbladder dorsal to foregut

fringing fulcra

Neopterygii (Permian)

NODE

sympletic jaw joint

highly mobile maxilla

Teleost (Triassic)

maxilla is pulled in and lower jaw is pushed out

Sarcopterygii (Silurian)

NODE

large clavicle

beginning of pectoral girdle evolution

lobed fins/fleshy limbs

Coelacanth (Devonian)

sarcopts

Choanate (Devonian)

NODE

Front and back halves of braincase fuse

Stapes

Ossified inner ear capsule

Pectoral girdle free from skull

Pectoral and pelvic girdles articulate w. vertebral column

Polydactyl limb

Complex intervertebral articulations

Tetrapod (Devonian)

NODE

weight bearing joints

poldactyl fingers

stapes

Stapes

evolved from hyomandibula (jaw) for sound

Amphibia (Devonian)

NODE

flat skull w. widely separate internal nares

Intercentrum

4 digit manus

Temnospondyl (Carboniferous)

NODE

arge interpterygoid vacuities, double occipital condyle

Lissamphibian (Permian)

Pedicellate teeth (Dissorophids juveniles too)

intercentrum dominant

Lepospondyl (Carboniferous)

NODE

tabular parietal contact in skulls

Lepospondyl skull

Amniote (Carboniferous)

NODE

astragalus (3 fused tarsals)

atlas-axis complex

amniotic egg

internal fertilization

waterproof scales/skin

large, complex lungs

loss of lateral line system

loss of otic notch

Anthracosaur (Carboniferous)

NODE

pleurocentrum dominant

intercentrum vs pleurocentrum dominant

Synapsid (Carboniferous)

NODE

a single pair of temporal openings (fenestrae) in the skull behind the eye sockets

mammals and kin

Increased oral processing of food

Elevated levels of metabolism

Therapsid (Permian)

NODE

Enlarged temporal opening faces dorsally

Incised angular bone

Initial changes toward upright posture

Cynodont (Permian)

NODE

Mammal (Triassic)

DS jaw joint

Groups to know

Dueterostomes (NODE)

Echinoderms

Hemichordates

Chordates (NODE)

Urochordates

Cephalochordates

Vertebrata (NODE)

Heterostracans

Lamprey

Osteostracans

Anaspids

Gnathostomes (NODE)

Placoderms

Acanthodians

Osteichthyes (NODE)

Actinopterygiians (NODE)

Polypterus

Neopterygiian (NODE)

Teleost

Sarcopterygiian (NODE)

Coelocanths

Lungfish

Tetrapods (NODE)