Lecture 18 Flashcards
Echinodermata stratigraphic range
Ordovician-present
Echinoderma meaning
Spine skin
Echinodermata general morphology
Triploblastic metazoan
Echinodermata ecology
Exclusively marine, benthic invertebrates
Echinodermata life mode
Mobile or sessile
Free reproduction/fertilization in water column
Male and female individuals
Larval stage characterized by bilateral symmetry
Echinodermata 3 important features
Pentaradial symmetry
Discontinuous mesodermal exoskeleton (just below skin)
Ambulacral system
Ambulacral system
Internal water-vascular system of canals (serves locomotion, feeding, respiration)
Echinozoa example
Sea urchins
Echinozoa stratigraphic range
Ordovician-recent
Crinozoa example
Sea lilies
Crinozoa stratigraphic range
Middle Cambrian-recent
Blastozoa stratigraphic range
Silurian-Permian
Echinozoa composition
Calcareous test
Echinozoa life mode
Herd-behaviour
Vagile
Benthic
Echinozoa ecology
Shallow environment - often coastal
Exclusively marine, graze on algae and small animals, or filter feed
Madreporite
Perforated plate by which the entry of seawater into the vascular system is controlled
Tube feet
Protrude out through holes in skeleton
Connected to the water vascular system, operate through hydraulic pressure
Used for locomotion, feeding, respiration
Aristotle’s lantern
5 teeth
Masticory organ (mouth)
Regular echinoids
Spherical
Epibenthic
Irregular echinoids
Migration of the anus
Aristotle’s lantern reduced or lost
Flattened shape
Endobenthic
Crinozoa general morphology
Pentaradial symmetry
Two main body parts
Two main body parts of Crinozoa
Stalk made of individual columnals
Crown with calyx and flexible arms
Crinozoa stratigraphic range
Ordovician-present
