Week 3: Species Identification Through Bones

Taxonomy

Classification of organisms hierarchically

Taxon

A named group of organisms who share a certain number of common characteristics

Eukarya

Domain of taxonomy where all organisms have a clearly defined nucleus in their cells.

Binomial nomenclature

System using the genus and species, developed by Carolus Linnaeus

Chordata

Kingdom where all animals have a notocord in their embryology

Mammalia

Class where all animals feed milk from mammary glands + have hair.

Perissodactyla

Order classifying ungulates with odd number of toes in their hindlimbs.
Midgut fermenters
(e.g. horses)

Artiodactyla

Order classifying ungulates with even number of toes in their hindlimbs.
These have a foregut fermenting, herbivorous diet so lack incisors
(e.g. deer, sheep, goats, cows, pigs)

Carnivora

Order classifying carnivores
(e.g. cats, dogs, foxes, otters, badgers, weasels)

Convergent evolution

Anatomical similarities that have evolved from 2 very different species to meet the same function
(e.g. european and african golden mole)

Bovidae

Type of artiodactyla with horns
(cows)

Cervidae

Type of artiodactyla with antlers
(deer)

Equidae

Type of perissodactyla (horse)

Tapiridae

Type of perissodactyla with even digits in the forelimbs
(tapiers)

Rhinocerotidae

Type of perissodactyla (rhino)

Rodentia

Order classifying lots of rodents. Most diverse order, with each sub-order based on skull, jaw, and teeth anatomy.
They have big orbits and large tympanic bulla

Sciurudae

Sub-order of rodentia (squirrel)

Muridae

Sub-order of rodentia (rats, mice, hamsters, gerbils)

Caviidae

Sub-order of rodentia (guinea pigs, capybara, chinchillas, beavers, porcupies)

Infraorbital foramen

Opening under the orbit with the masseter muscle running through in rodentia for gnawing

Lagomorpha

Order classifying rabbits, hares, and pika.
Teeth look like rodents (convergent evolution).
The maxilla is open!

Peg teeth

Extra set of incisors in rabbits (lagomorphs). These are shorter than normal incisors and help the lower incisors be more chisel-like.

Soricomorpha

Order classifying shrews and european moles. Their teeth aren't as specialised but do face backwards. This is to help catch insects.
Small orbits.

Antlers

Seasonal, fast-growing, entirely bone, branched, and grow from a pedicle. These are on deer (generally only males)

Horns

Non-seasonal structures formed from the frontal bone, covered by a keratin sheath. Non-branched on both males and females.
e.g. on cows

Taphonomy

Processes after death that modify anatomy.
- Cultural (human changes)
- Biological (effect of animals/plants)
- Physical (weathering, abrasion, pressure)
- Chemical (pH, soil type, groundwater)