Taxonomy Flashcards
(23 cards)
What defining character separates Porifera from the rest of the metazoans?
Tissue. In Porifera, cells are not organized into tissues.
What character separates Cnidaria from the rest of the metazoans?
Bilateralism - 2 separate, distinguishable sides that are often symmetrical.
Which phyla is the first to exhibit a coelom?
Platyhelminthes.
What character occurs on the branch before Annelida and Arthropoda?
Protostome body plan - mouth forms first.
What character occurs on the branch before Bivalvia, Gastropoda and Cephlapoda?
Mollusca.
Where do deuterostome features appears on the metazoan clade?
Between the branch with Arthropoda/Annelida and Brachiopod and Bryozoa.
What character occurs before Brachiopoda and Bryozoa?
Lophophore - Organ for respiration and feeding.
Which feature distinguishes Echinodermata and Chordata from the rest of the clade?
Mesodermal Skeleton - fleshy ectoderm tissue.
Features of Porifera:
Sponges: Some have skeletons, not extensive in fossil record, independent cells, Parazoans
What tissue layers exist in diploblastic organisms?
An ectoderm(outer) and endoderm(inner)
Features of Cnidaria:
Hydrozoans, sea anemones, corals, jellyfish:
Usually soft-bodied; not great for fossils.
Except for corals; hard bodies and good fossil records.
Can be solitary or colonial
Features of Platyhelminthes:
Flat worms
- Triploblastic
- not very good fossil record
- possibly responsible for a lot of evolutionary progress
What is a coelom?
A fluid filled cavity which houses organs - a buffer layer.
Features of Arthropoda:
Myriapods(Centipedes, millipedes); Trilobites; Crustaceans; Insects; Chelicerates(Spiders, arachnids, mites, scorpions)
- Most dominant phyla on Earth in terms of species richness
- Terrestrial species; Poor fossil record
- Marine ; decent record
Features of Gastropoda, Cephlapoda, and Bivalves:
Cephalopoda: Squid, cuttlefish, octopus, ammonoids
Gastropoda: Snails, slugs
Bivalves: clams, oysters, mussels, scallops
Features of Bryozoa:
- “Moss animals”
- Tend to be very tiny
- extremely resilient
- always colonial
Features of Brachiopoda:
- Always solitary.
- Look like clams, not closely related.
Features of Echinodermata:
Sea urchins; seastars; sand-dollars; Sea Lillies; sea biscuits.
- Fleshy ectoderm tissues.
- Regenerative features.
- Mobile or sessile.
Describe taphonomy:
Taphonomy is everything that happens to an organism from the time it dies until it is “discovered”. These processes inhibit (with exceptions) the process of fossilization.
Names the 3 taphonomic processes and examples:
- Biological: Predators, scavengers, exposure to oxygen.
- Physical: Transport and Compaction.
- Chemical: Dissolution. (Groundwater-slightly acidic. dissolves shell material)
What are some features associated with significant transport of an organism?
a. Abraded features on surface.
b. Rounding of edges.
c. Fragmentation.
d. Winnowing - size bias.
e. Out of life orientation.
f. Preferred orientation with primary flow direction.
What conditions are most favourable in fossilization?
a. Rapid and deep burial - more likely to stay buried. Avoids some of the taphonomic processes.
b. Location with high rates of sedimentation - Shallow seas, basins (low rates of erosion; high rates of sed)
c. Location with favourable water chemistry (Saturated with minerals like Mg, Ca, etc. )
Linnean Classification:
Kingdom
Phylum
Class
Order
Family
Genus
Genus species (italicized)