CVA Vocab Words 1

Phylogeny

evolutionary history of a group of organisms, as represented by a phylogenetic tree or dendrogram

Systematics

study of evolutionary relationships among different taxa and their classification

Taxonomy

describing and classifying species

Tip (phylogenetics)

endpoints of a phylogenetic tree, representing the most recent taxa or units being studied

Branch (phylogenetics)

lines connecting two or more nodes in the phylogeny

Node (phylogenetics)

where branches meet in a phylogeny, representing ancestors

Clade

a group of organisms evolved from a common ancestor

MRCA

most recent common ancestor of a group of organisms

Homology

similarity of structures due to inheritance from a common ancestor

Synapomorphy

shared, derived traits or features

Symplesiomorphy

shared, ancestral traits or features

Homoplasy/convergence

similarity of character states due to similar function, NOT inheritance

Monophyly

a group of organisms sharing a common ancestor (MRCA & ALL descendants)

Paraphyly

group including the common ancestor, but not all descendants (MRCA & NOT all descendants)

Polyphyly

group derived from more than one common ancestor (NO MRCA & descendants)

Anagenesis

evolution along branches (of a phylogeny)

Cladogenesis

evolution (speciation) at nodes (of a phylogeny)

Blastula

early developmental stage of animal embryo when it is a hollow ball of cells

Gastrula

later embryonic stage when the blastula invaginates to form an inner gut tube

Archenteron

early or rudimentary gut tract of an embryo

Blastopore

opening of the central cavity of an embryo during gastrulation

Blastocoel

central cavity of the blastula

Ectoderm

external tissue layer of embryo; gives rise to epidermis and nerves in adults

Endoderm

innermost tissue layer of embryo; give rise to gut lining and organs

Mesoderm

middle embryonic tissue layer; gives rise to diverse organs like muscle

Diploblastic

animals having only two embryonic tissue layers (many non-deuterostomes)

Triploblastic

animals having three embryonic layers (like deuterstomes)

Gastrulation

process where an embryonic blastula invaginates to form a gastrulaN

Neurulation

the process of transforming the flat neural plate into a neural tube

Neural Crest

putative 4th germ layer, gives rise to cranial cartilage/skeleton, odontoblasts, pigmentation

Neural Placodes

ectodermal derivative, gives rise to sensory epithelia, cranial ganglia, & lateral line

Notocord

rod-like, rigid tube supporting the skeleton of chordates

Dorsal Hollow Nerve Cord

central nervous system structure dorsal to the notocord

Post-anal Tail

tail that extends past the anus; used for locomotion (and burial in some)

Pharyngeal pouch or slits (pharynx)

feeding structure in chordates, used like a sieve for filtering

Endostyle

longitudinal, ciliated groove in pharynx; used to gather food (homologous w/thyroid)

Isoosmotic

having the same osmotic pressure as surrounding environment

Hyperosmotic

having higher osmotic pressure as surrounding environment

Cephalization

concentration of sense organs at the anterior (head) of the body

Cranium

part of the skull that encases and protects the brain

Hermaphroditic

a sexually producing organism that produces both male and female gametes

Hemal Arches and Neural Arches

ventral and dorsal spinous projections of the vertebrate

Vertebral Centra

the ossified central section of the vertebrae

Arcualia

primordial or rudimentary vertebrae, made of cartilage

Synarcual

fused series of vertebral elements

Heterocercal Tail

tail in which the vertebral column extends into one lobe (usually the upper)

Myomeres

blocks of skeletal muscle arranged in sequence along the flanks

Semicircular canals

interconnected tubes located in the inner ear, used to sense movement and orientation

Ammocoete Larvae

juvenile stage of lamprey, resembles a cephalochordate

Gill (branchial) Arches

the cartilaginous or bony skeleton supporting the gill filaments

Mandibular Cartilage

the lower 1st branchial (gill) arch, becomes lower jaw

Palatoquadrate Cartilage

the upper 1st branchial (gill) arch, becomes the upper jaw

Spiracle

remnants of the 1st gill slit, used for ventilation in benthic fishes like rays

Operculum

bony or cartilaginous plate which covers the gills in ratfishes, acanthodians, and bony fishes

Placoid Scales

tooth-like odontodes that cover the body surfaces of cartilaginous fishes

Ceratotrichia

stiff collagenous filaments which support the fins of cartilaginous fishes

Lepidotrichia

the bone-reinforced collagenous fin filaments which comprise the fins in bony fishes

Oviparous

egg-laying

Viviparous

live-bearing, having live young

Ovoviviparous

embryos that develop inside eggs that remain in the mother’s body until they are ready to hatch

Choanae

internal opening into the mouth, connecting to the external nostrils (nares)

Cosmoid Scales

scales with inner bone layer and outer dentine (cosmine)

Diphycercal Tail

symmetric tail fin in which the vertebral column extends to the tip

Labyrinthodont Teeth

teeth with deeply-folded enamel structure

Tiktaalik

fossil sarcopterygian fish resembling modern amphibians and tetrapods

Chiridium

muscular limb with well-defined joints and digits

Acanthostega + Ichthyostega

early amphibian-like tetrapods

Pectoral Girdles and Pelvic Girdles

shoulder and hip skeleton supporting the fore- and hind-limbs

Cutaneous Respiration

respiration using the skin

Metamorphosis

transformation process from an immature juvenile to an adult form

Saltation

jumping or hopping form of locomotion

Bipedalism

walking erect on two legs

Carapace + Plastron (Turtles)

the top and bottom of a turtle’s shell, respectively

Fossorial

organisms which burrow and/or spend their life underground

Tympanum

membrane comprising the eardrum, used to sense sound in air

Cleidoic Egg

a shelled, waterproof egg with specialized internal membranes that allows amniotes to reproduce on land

Temporal Fenestrae

lateral openings in the skills of amniotes

Endothermy

maintaining a constant internal temperature; body temperature maintained mainly by the animal’s own metabolism

Mammary Glands

milk producing glands in mammals

Marsupium

the pouch in marsupials

Placenta

organ that provides oxygen and nutrients to a fetus, while removing wastes

Ectothermy

external heat dependence, body temperature regulated by environment

Poikilothermy

variable body temperature, internal temperature fluctuates with the environment

Oviparity

egg-laying, embryos develop inside eggs, receive nourishment from yolk

Viviparity

live birth, embryos develop inside the mother and receive direct nourishment via placenta

Ovoviviparity

embryos develop inside eggs that remain within the mother until hatching, nourished by yolk, but resulting in live birth

Matrotrophy

where parent organisms provide nutrient subsidy to developing young

Sebaceous Glands

sweat producing glands in mammals