Taxonomy

Question 1

What defining character separates Porifera from the rest of the metazoans?

Answer 1

Tissue. In Porifera, cells are not organized into tissues.

Question 2

What character separates Cnidaria from the rest of the metazoans?

Answer 2

Bilateralism - 2 separate, distinguishable sides that are often symmetrical.

Question 3

Which phyla is the first to exhibit a coelom?

Answer 3

Platyhelminthes.

Question 4

What character occurs on the branch before Annelida and Arthropoda?

Answer 4

Protostome body plan - mouth forms first.

Question 5

What character occurs on the branch before Bivalvia, Gastropoda and Cephlapoda?

Answer 5

Mollusca.

Question 6

Where do deuterostome features appears on the metazoan clade?

Answer 6

Between the branch with Arthropoda/Annelida and Brachiopod and Bryozoa.

Question 7

What character occurs before Brachiopoda and Bryozoa?

Answer 7

Lophophore - Organ for respiration and feeding.

Question 8

Which feature distinguishes Echinodermata and Chordata from the rest of the clade?

Answer 8

Mesodermal Skeleton - fleshy ectoderm tissue.

Question 9

Features of Porifera:

Answer 9

Sponges: Some have skeletons, not extensive in fossil record, independent cells, Parazoans

Question 10

What tissue layers exist in diploblastic organisms?

Answer 10

An ectoderm(outer) and endoderm(inner)

Question 11

Features of Cnidaria:

Answer 11

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

Question 12

Features of Platyhelminthes:

Answer 12

Flat worms
- Triploblastic
- not very good fossil record
- possibly responsible for a lot of evolutionary progress

Question 13

What is a coelom?

Answer 13

A fluid filled cavity which houses organs - a buffer layer.

Question 14

Features of Arthropoda:

Answer 14

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

Question 15

Features of Gastropoda, Cephlapoda, and Bivalves:

Answer 15

Cephalopoda: Squid, cuttlefish, octopus, ammonoids
Gastropoda: Snails, slugs
Bivalves: clams, oysters, mussels, scallops

Question 16

Features of Bryozoa:

Answer 16

• “Moss animals”
• Tend to be very tiny
• extremely resilient
• always colonial

Question 17

Features of Brachiopoda:

Answer 17

• Always solitary.
• Look like clams, not closely related.

Question 18

Features of Echinodermata:

Answer 18

Sea urchins; seastars; sand-dollars; Sea Lillies; sea biscuits.
- Fleshy ectoderm tissues.
- Regenerative features.
- Mobile or sessile.

Question 19

Describe taphonomy:

Answer 19

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.

Question 20

Names the 3 taphonomic processes and examples:

Answer 20

1. Biological: Predators, scavengers, exposure to oxygen.
2. Physical: Transport and Compaction.
3. Chemical: Dissolution. (Groundwater-slightly acidic. dissolves shell material)

Question 21

What are some features associated with significant transport of an organism?

Answer 21

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.

Question 22

What conditions are most favourable in fossilization?

Answer 22

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. )

Question 23

Linnean Classification:

Answer 23

Kingdom
Phylum
Class
Order
Family
Genus
Genus species (italicized)