Mammalogy Flashcards
What is binomial nomenclature?
The scientific assignation of species with two parts: Genus and species. These should be italicized or underlined if written in script.
What are species?
Species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups and share a common gene pool
What is the hierarchy of classical classification?
Domain Kingdom Phylum Class Order Family Genus species
What are the three types of classification?
- Numerical taxonomy
- Evolutionary taxonomy
- Phylogenetic systematics (cladistics)
What is a clade?
A clade is a monophyletic group
What is a homologous character?
A character state inherited from a common ansestor
What are analogous characters?
Characteristic that has a similar function but arose independently with no common ancestry
What is convergent evolution?
Similar features arise from different ancestors as a result of similar ecological characteristics
What is another name for convergence?
Ecomorph
What is parallel evolution?
Independent modifications from the same ancestor
What is homoplasy?
Similar character state that misrepresents common descent as a result of convergence, parallelism, or reversal
What is molecular phylogeny?
The use of genetic differences in regards to the number of base pairs different to determine divergence on a molecular clock
What are synapomorphies?
Shared derived characteristics
What are symplesiomorphies?
Shared characteristics by the ingroup and outgroup that do not help in phylogenetic relationships
What are the general steps to the reptile mammal transition?
pelycosaurs to primitive therapsids to advanced therapsids (cynodonts) to mammals
What is Synapsida?
a monophyletic group that includes mammals; characters include a single temporal opening below postorbital and squamosal skull elements; dominant in early Triassic and in Cenozoic
What are Pelycosauria?
A paraphyletic group of primitive synapsids; reptile-like posture, skull, lower jaw, dentition; dominant in Permian period
What are Therapsida?
paraphyletic grade betwen pelycosaurs and mammals domiant during late Permain and early Triassic
What is Mammalia?
Established in the late Triassic, this group began in the Mesozoic era, increasing before dinosaurs went extinct, and increasing in size; still present today
What are the different eras in geological history?
Proterozoic Paleozoic -Cambrian -Ordovician -Silurian -Devonian -Carboniferous --Mississippian --Pennsylvanian -Permian Mesozoic -Triassic -Jurassic -Cretaceous Cenozoic -Paleocene -Eocene -Quaternary
What are the pulses of synapsid evolution?
Pulse 1 (Permian) - Pelycosaurs - sprawling posture, ectothermic, tropical Pulse 2 (Early to Mid Triassic) - Therapsids - increased metabolic rate, improved posture, greater jaw musculature, tropical and temperate Pulse 3 (Late Triassic) - Cynodont Therapsids - some endothermy, diaphragm, secondary palate, differentiated dentition, masseter muscle of jaw, separation of articular, quadrate, and angular bones of jaw Pulse 4 (Late Triassic to Early Cretaceous) - early true mammals - lactation, endothermic, wide geography, low diversity Pulse 5 (Cretaceous) - Therian mammals - tribosphenic molars (crush and sheer), placentals and marsupials diverge Pulse 6 (Early Paleocene to Middle Eocene) - Archaic therians and didelphoic marsupials - tropical forest type characters, first carnivores, first semi-aquatic herbivores Pulse 7 (Late Eocene to recent) - Modern therians, confined marsupials - diverse habitats, various sizes
What are the features of a tooth structure?
Crown - above gums Root - below gums Enamel - outer layer Dentin - inner layer Pulp - holds blood vessels and nerves Cementum - spongy, bone-like material hold tooth is socket Periodontal membrane Nerve and blood supply
What are the four major types of teeth implantation?
- Acrodont - attached to the surface of the bone or in a shallow depression
- Pleurodont - teeth are attached on a shelf
- Thecodont - teeth are in a socket (mammals)
- Gomphodont - multiple-rooted teeth (molars)
What is monophyodont, diphyodont and polyphyodont?
Moophyodont - one set of teeth
Diphyodont - two sets of teeth
Polyphyodont - multiple sets of teeth
What types of teeth are there?
Incisors - on premaxilla and dentary
Canines - on maxilla and dentary
Cheek teeth (premolar and molar) - post-canine, maxilla, and dentary
What is homodont and heterodont?
Homodont - similar tooth structure in mouth
Heterodont - different types of teeth in mouth
What is edentulous?
No permanent teeth
What is integument?
Glands of several types, hair follicles, fatty tissue, sensory endings, claws, hooves, nails, etc.
What are the functions of integuments?
Insulation, protection, sweating (homeostasis), reception of sensory information
What is pelage?
Whole body hair. This includes underfur (down or wool), and overfur (guard hairs).
What are the five stages of hair development?
- Follicle development - prenatal
- Anagen - hair growth, phase determines length
- Catagen - regression, cell division stops, apoptosis push up the follicle
- Telogen - rest, just below sebaceous gland, club shaped instead of bulb shaped
- Exogen - exit of hair shaft from follicle
What are hairs made of?
Three layers of keratin - a central core or medulla, layer of cortex surrounding the medulla, and an outermost layer called the cuticle
What are vibrissae?
Whiskers; specialized sensory hairs
What are the three skin glands? What are their purposes
Allow evaporative cooling and elimination of some wastes
Sebaceous glands - oily secretion for lubricating hair and skin to keep pelage dry
Scent and musk glands - social communication, marking territory, attracting mates, protection
What are mammary glands?
lobules of glandular tissue enclosed in connective tissue capsules the converge to a nipple or cistern for lactation