Paleo 203 Midterm Condensed

Thrust

The force that generates propulsion.

Appendicular skeleton

The bones that form the limbs and limb girdles. Includes all bones of the shoulders, arms, hips, and legs.

Appendicular locomotion

Motion generated by movement of the limbs. Have flippers or webbed feet to increase thrust and surface area

Flippers

Flatter bones, shorter radius, humerus, ulna, longer and numerous phalanges, covered in smooth flat tissue

Axial skeleton

The bones that form the mid-line of the body. Includes all bones of the skull, spinal column, and ribs.

Axial locomotion

Motion generated by movement of the spinal column. Developers caudal fluke to increase surface area

Caudal fluke

An expanded, soft-tissue fin supported by the last tail vertebrae. Vertical in marine reptiles, horizontal in marine mammals.

Collagen

A structural protein found in connective tissues of animals.

Anguilliform locomotion

A form of axial locomotion in which the entire spinal column undulates, propagating waves of muscle contractions down the entire body. Low efficiency. Animals that use this form of locomotion tend to be long and skinny. Ex. Sea snakes and eels

Thunniform locomotion

A form of axial locomotion in which only the tail undulates. Maximum efficiency. Animals that use this form of locomotion tend to be torpedo-shaped. In high speed predatory fish, not body oscillation, crescent shaped fins and fluke. Ex. Tuna, dolphins

Carangiform locomotion

A form of axial locomotion in which only the back half of the spinal column undulates. Animals that use this form of locomotion tend to be spindle-shaped. ex. Seals, crocs, marine iguanas

Pitch

Up and down motion. One of three planes of motion in a 3D environment.

Roll

Movement where an object turns over on its forward-backward axis. One of three planes of motion in a 3D environment.

Yaw

Left and right motions. One of three planes of motion in a 3D environment.

Dorsal fin

An unpaired fin on the back of an animal which helps to stabilize them against rolling.

Drag

The force that resists the movement of an object through any medium. Increased by both density and viscosity of the medium.

Inertial drag

The force that resists the movement of an object by disturbing the flow of molecules around that object crates a space where the medium fills and pulls body backward. It is based on the density of the medium through which it moves. Needs fusiform body shape, smooth, elongate, decreased surface area, loss of hind limbs and external ears

Fusiform

An oblong morphology that tapers at both ends. Can be described as spindle-shaped or torpedo-shaped.

Viscous drag

The force that resists the movement of an object based on friction generated between the object and the medium it is moving through. Caused by the viscosity of the medium through which it moves. Needs smooth, hairless body

Lactic acid

An organic acid produced in muscles during strenuous activity when there is little oxygen available. Causes muscle fatigue and soreness. In crocs

Nares

Openings in the skull that allow for the passage of air from the nostrils to the windpipe.

Blowhole

Nostrils that have migrated to the top of the head in a marine mammal.

Neutral buoyancy

When an object has the same density as the medium that surrounds it. The object with neither sink nor float.

Pachyostosis

A condition in which bones become denser and larger due to increased growth of the denser outer layers of the bones. In manatees, penguins, early whale relatives

Osteosclerosis

A condition in which bones become denser, but not larger, due to increased mineralization usually in the spongy inner regions of the bones. In walrus and turtles

Salt gland

A special gland that concentrates salt from the blood so that it can be expelled from the body. On crocs tongue, under sea snake tongue, above sea turtle and bird eyes, connected to nostrils in marine iguanas (expel by sneeze)

Metabolism

The sum total of all chemical processes that occur within an organism in order to maintain life. Hard to maintain in water because water is a good heat conductor

Underhairs

The shorter, finer hairs close to the skin of a mammal. Function primarily as insulation. Traps heat near skin

Guard hairs

The outer layer of longer, coarser hairs on a mammal. Functions primarily as protection. Keeps water away from underhairs. Layer like shingles

Tapetum lucidum

A lining on the back of the eyes that reflects incoming light through the retina a second time, increasing the effectiveness of the eye in low light conditions. Seals, crocs, cats

Water properties related to sight

1. Density changes how light bends - bends less in water
2. Light doesn’t travel as far and diffracts
3. Only some spectrum of light is seen in greater depths - blue and green penetrate deeper, total darkness at 200m

Bone conduction

The transmission of sound waves from the surrounding environment to the inner ear through the skull bones. Uses vibrations, less distortion, secondarily aquatic adaptation

Hearing in water

Easier to hear in water, travel 5x faster

Echolocation

A type of sonar used by some animals to detect objects. The animal emits high-pitched sounds which bounce off of surrounding objects and back to the animal's ears, revealing the location of the objects.

Paleoecology

(see ecology) The ecology of extinct organisms.

Marine Reptile clades

Ichthyoperygians, sauropterygians, mosasauroids

When first tetrapods colonized

During Devonian

Anapsid

Having no temporal fenestrae in the skull.

Synapsdid

Having one pair of temporal fenestrae in the skull.

Diapsid

Having two pairs of temporal fenestrae in the skull: the laterotemporal and supratemporal fenestrae.

2 diapsida lineages

Archosauromorpha, Lepidosauromorpha

Synapsida (informally, synapsids)

With the Sauropsida, is one of the two major divisions of amniotes. This group have only one temporal fenestra. Mammals are the modern representatives of this group.

Sauropsida (informally, sauropsids)

With the Synapsida, is one of the two major divisions of amniotes. This group has two temporal fenestrae. Crocodiles, lizards and birds, Parareptiles and diapsida

Parareptilia (informally, parareptiles)

With the Diapsida, is one of two major divisions within the Sauropsida. Has the anapsid skull condition.

Diapsida (informally, diapsids)

With the Parareptilia, is one of two major divisions within the Sauropsida. Has the diapsid skull condition.

Laterotemporal fenestra

The lower of two temporal fenestrae in the diapsid skull condition, found below and/or behind the eye.

Supratemporal fenestra

The upper of two temporal fenestrae in the diapsid skull condition, found above and/or behind the eye.

Archosauromorpha (informally, archosaurs)

Ruling reptiles. With the Lepidosauromorpha, is one of two major divisions of the Diapsida. Have an additional fenestra in front of the eye and on the jaw. Members include birds, crocodiles, dinosaurs and pterosaurs.

Lepidosauromorpha (informally, lepidosaurs)

Scaly Reptiles. With the Archosauromorpha, is one of two major divisions of the Diapsida. Members include lizards and snakes. No extra temporal openings

Water density

Results in resistance when swimming, push against this to produce thrust

Ichthyopterygia (informally, ichthyopterygians)

A group of aquatic diapsids best known for their most derived members- the ichthyosaurs, eurryapsids

Euryapsid

A skull condition with one temporal opening, derived from the diapsid condition. Developed in ichthyopterygians when the lower temporal fenestra disappeared due to reduction of the back part of the skull.

Gastralia

A series of long slender bones found in the ventral region of the body that provide support and protection to the abdomen and can serve as muscle attachment sites. Also known as "belly-ribs".

Articulate

When bones fit together and form a joint or suture.

Amphicoelous

A type of vertebral shape where both articulating surfaces are concave.

Plicidentine

A type of tooth tissue in ichthyopterygians where the inner tooth tissues have a distinct folded pattern.

Centrum

The solid central part of a vertebra, to which the processes and spines are attached.

Ichthyopterygian Locomotion

Axial, with reduced articulation in spine and pelvic girdle, fully aquatic, pelvic bones float in layers of muscles in the wall of the abdomen, decreased amount of joints between hind legs, shorter less flexible centra, plate like vertebrae, neural spines less attached

Fluted

Grooved. With the appearance of having columns.

Neural spines

Arched vertebral processes that protect the spinal cord and provide sites for muscle attachment. Become simplifies in ichthypoterygians

Sclerotic ring

A ring of bone inside the eyes that helped to support and focus the eyeball.

Ram feeding

A type of underwater feeding strategy where the predator moves through the water with its mouth open, engulfing the prey and the water surrounding it. Also known as filter feeding. Water inhaled flows out the gills and strained with gill rakers

Lunge feeding

A type of ram feeding where a predator takes in a large mouthful of prey and water, and then pushes the water out through a filter such as baleen, leaving the prey in trapped in the mouth.

Baleen

A fibrous material that has replaced the teeth of some whales. Used a filter during lunge feeding.

Manipulation

A feeding strategy where teeth are the instruments used to capture prey. Used for prey on the seafloor of big bites of large open water prey

Feeding guilds

Groups of species, not necessarily closely related, that use similar resources in their environments.

Crush guild

An aquatic feeding guild whose members possess robust teeth for crushing hard-shelled prey such as molluscs.

Smash guild

An aquatic feeding guild whose members possess small teeth with rounded points for eating soft-prey such as squid.

Pierce guild

An aquatic feeding guild whose members possess long, pointed teeth for trapping and piercing small, slippery prey such as small fish.

Cut guild

An aquatic feeding guild whose members possess pointed teeth with cutting edges for tearing apart large prey. In apex predators

Heterocercal

A tail shape where one lobe is longer than the other. In basal ichysosaurs, had cartilaginous blade to support short top lobe, downward tail bend. Ex. Mixosaurus

Homocercal

A tail shape where both lobes are approximately the same length. 2nd derived tails in ichyosaurs. Ex. Platypterygians

Basal Ichthyopterygian Locomotion

Long serpentine bodies, not for high speeds, long distance predators ambushed prey, good at quick turns ex. Utatsussaurs, chaohussaurs

Derived Ichthyopterygian Locomotion

Chased and manipulated prey, streamlined tuna-like bodies, short torso, crescent shaped tail fluke, high energy cruising, pursuit predators. Ex. Stenopterygians

Hyperphalangy

The condition where the digits of an organism have more phalanges than seen in the ancestral state.

Hyperdactyly

The condition where an organism has more digits (fingers or toes) than seen in the ancestral state.

Avascular necrosis

The death of bone tissue caused by a lack of blood supply leading to tiny breaks in the bones, and areas of collapse. In diving animals, can be caused by a rapid ascent, when dissolved gases in the blood form bubbles that block blood vessels.

The Bends

A condition in diving animals where rapid ascent can lead to blood supply being cut off. Also known as decompression sickness. See avascular necrosis.

Photoreceptors

The structures or cells, such as those that line the back of the eyeball, that respond to light.

Aperture

The space through which light passes in an optical instrument such as the eye. Bigger one means more likely to have depression sickness, biggest in ophthalmosaurus

Endothermy

Generation ad regulation of body heat using the body's metabolism. This property is also known as being warm-blooded.

Ectothermy

Regulation of body heat using external sources such as the sun. This property is known as being cold-blooded.

Viviparous

Where an animal gives birth to live young that have developed inside the body of the parent.

Oviparous

Where an animal lays eggs that then hatch after they have been laid.

Gregarious

Animals lives in groups or communities. Found in 40 shinosaurus in a mass bone bed that probably dies from red tide

Ichthopterygian Endothermy proof

1. Large size
2. Ring like growth patterns in limb bones
3. Viviparity - had 12 live young

How baby’s are pushed out of dead moms

Gases from death provide pressure to expel dead fetus, can be preserved as fossils

Niche

The role an organism plays in its ecosystem.

Middle Triassic

Thalattoarchon (1st apex predator) evolved, took 30 million years to repopulate after end-Permian mass extinction occupied high variety of ocean niches

Early Triassic

Middle Triassic

Late triassic

Late Triassic

High morphological and taxonomic diversity, extinction due to Pangea breaking up, deadly climate change (increased volcanic activity and tectonic activity, affected plankton), evolutionary bottleneck

Evolutionary bottleneck

When extinction reduces the number of individuals within a group, the number of species that make up a group (the diversity), the variety of morphologies within the group (the disparity), or a combination thereof.

Early Jurassic

Only thunnosauria remained after bottleneck, long distance swimming helped to survive climate changes, 1 niche - squid eaters, sauropterygians, sharks, crocs, bony fish filled other niches, holzmaden lagerstatten

Early Jurassic

Fully aquatic

Middle Jurassic

Laggerstatten

A deposit of extraordinary fossils with exceptional preservation, sometimes including soft tissues.

Mary Anning

A young woman from the early 1800s of England. She was a fossil collector, dealer and paleontologist, and was responsible for many discoveries including the first correctly identified ichthyosaur, the first two plesiosaurs, the first pterosaur found outside of Germany, and numerous other discoveries.

Holzmaden

A laggerstatten from Germany preserved in oil shale. It is most famous for the large number of exquisitely preserved ichthyosaurs showing skin, muscle fibres, body outlines, embryos, and stomach contents.