L1 Bevan - Vertebrate Origins and Diversity Flashcards
Define taxonomy
the description, identification and classification of species.
Define nomenclature
a standardized system of naming taxa
Define systematics
the study of biological diversity using phylogeny - the evolutionary history and relationship between groups of organisms
What are chordates?
chordates are animals with bilateral symmetry that belong to the clade of animals know as the deutrostomes
What are the 3 subphyla in Chordata?
- Urochordata - tailed
- Chephalochordata - head
- Vertebrata
Why are vertebrate a good model for studying evolution? give 6 points
- monophyletic group
- free living
- basic anatomy and development in common with each other
- the diversity shown in the form and function can be related to adaptions and evolution
- best studied eukaryotic group
- good fossil record
What kind of skeleton do Agnatha have?
Cartilaginous skeleton - characterised by absence of paired fins
What are the 2 extanct groups of Agnatha?
Hagfish
Lampreys
How long ago did bony fish arise, and then jawed fish?
bony 500mya, but took until 410mya for jawed fish to appear
What is the largest class of vertebrates around today?
Osteichthyes
What are the 2 subclasses of Chondrichthyes?
- elasmobranchs (sharks, rays and skates)
2. holocephali - chimaeras and ghost shark
What are shark scales called?
Dermal denticles - placoid scales
What are Batoids?
Skates and rays - flat bodies with pectoral fins developed into broad flat wing-like appendages.
What is the difference between skates and rays?
Rays are viviparous (live bearing) while Skates are oviparous (egg laying) ahd release their eggs in rectangular cases called mermaid purses
What are the 5 different types of pelagic zones?
- Epipelagic - surface to 200m
- Mesopelagic - 200-1000m
- Bathypelagic - 1000-4000m
- Abyssopelagic - 4000-seafloor
- Hadopelagic - ocean trenches
