Gorgonopsids and cynodonts.

Cynodonts gave rise to the mammals.  They had a great enlargement of the lower margin of the temporal fenestra, appearance of the masseter muscle (associated with chewing by cheek teeth), presence of cusps on cheek - well developed heterodonty, loss of ribs from lumbar region - diaphragm, well developed bony secondary palate, two occipital condyles, probably endothermic

Fur (insulation), monochromatic vision (seeing at night, only see grey)

From fossils: large olfactory bulbs (smell), large somatosensory region of cerebral cortex (touch), middle ear bones (keen hearing)

Modified synapsid

Bony secondary palate

Turbinate bones

Zygomatic arch

Auditory bulla

Two occipital condyles

Single bone in lower jaw - dentary

Regionally differentiated teeth

High gear ratios:  Fulcrum closer to in lever length that out lever length.  For very powerful forces, strong muscles

Low gear ratios: Fulcrum at equal distance, small muscle contraction/force, large arc of movement. (output force relatively large)

Stride length x Stride rate

Rate depends on: Speed of muscle contraction gait

Length depends on: limb/bone length, limb posture, spinal flexing, time off ground

Plantigrade:  entire foot on ground, humans

Digitigrade:  Only digits on ground, dogs and cats

Unguligrade: Nail on ground, ungulates

Do herbivores exhibit much spinal flexing?  Why?

Tidal volume (ml) X breathing rate per minute = pulmonary

(Tidal volume - anatomical dead space) X breathing rate = alveoli

Residual volume = Pulmonary ventilation - alveoli ventilation

How do antelope ground squirrels and camels cope with heat stress?

Carnivore: Easily digested food - short and simple digestive tract, rapid transit time

Herbivore: hard to digest food - use symbiotic microorganisms to break down cellulose, long and complex digestive tract, slow transit time, have specialised "fermentation vats" in digestive systems

Carnivore: Large sagittal crest for origin of large temporalis muscle, prominent coronoid process of mandible, very small pterygoid muscle (not much sideways movement) and relatively small masseter muscle.  Large canines, no diastema

Herbivores: Diastema separates molars and incisors, incisors used for clipping motion/molars for grinding, large pterygoid muscle for sideways movement, upper/lower jaw come together synchronously across molar surface, large masseter muscle, small temporalis muscle (less powered bite)

Hindgut: less efficient at extracting nutrients, occurs after "true" stomach and smal intestine, faster gut passage time, allows smaller sized animals and to feed on poorer quality food, some have very large caecum where most fermentation occurs

Describe the different foregut fermentations in ruminants and non-ruminants

Ruminants: Grass chewed in mouth, watter added via saliva, passed into large reticulorumen, regurgitated and chewed again then move back into reticulorumen, pass into omasum once small enough where water is absorbed, passes into abomasum where regular digestion occurs

Non-ruminants: Not regurgitated and rechewed, no restrition of food particle size before passing into true stomach, less efficient extraction of nutrients because of larger particle size and faster gut passage times, can survive on poorer quality pasture because of faster gut passage time (don't starve to death)