Deuterostomes: Graphtolites (Chapter 15)

Question 1

Phylum Hemichordata (notochord)

Answer 1

small, soft-bodied animals 
bilateral symmetry
lack of segmentation 
rod-like structure - notochord
colonial pterobranches
infaunal acorn worms
evolutionary link between echinoderms & chordates
Pre-Cambrian - Recent

Question 2

Class Graptolithina

Answer 2

theca, stipe
colonial - vague resemblance to bryozoan
typically preserved as carbonized traces
open water, low-energy, part of plankton that floats = neckton
abundant for Ordovician & Silurian (Lower Paleozoic)
sometimes significant biostratigraphic use
known to make to Carboniferous

Question 3

theca

Answer 3

structure where the graptolite lives

Question 4

stipe

Answer 4

the connection between thecas of graptolites