Practical handouts Flashcards
How is Nudds classification of lithostrontinidea divided?
3 sections based on growth form
What are the 3 sections of Nudds classification?
Fasciculate
Ceroid
Plocoid
What are the characteristics of class trilobita?
Marine arthropods with calcite exoskeleton divided longitudinally into three lobes. Appendages include one pair of uniramous antennae and a series of biramous appendages which decrease in size posteriorly
What is order REDLICHIIDA?
Cephalon large and semicircular, with genal
spines. Thorax with many spinose segments. Pygidium tiny
What are the 2 suborders of Redclichiida?
Suborder OLENELLINA - Dorsal facial sutures not seen.
Suborder REDLICHIINA - Opisthoparian
What are the characteristics of order Agnostida?
Small trilobites with two or three
thoracic segments. Usually blind. Isopygous (gamete fusion)
What are the characteristics of order CORYNEXOCHIDA?
Glabella expands anteriorly, often extending to front of cephalon. Commonly isopygous. Sub-order smoother.
What are the characteristics of order Lichida?
Spiny trilobites, which are opisthoparian and have the glabella narrowing forwards
What are the characteristics of order Phacopida?
Proparian or gonatoparian trilobites
What are the characteristics of order PTYCHOPARIIDA?
forwardly tapering glabella with straight glabellar furrows, a large thorax and small pygidium
What are the characteristics of order proetida?
relatively larger pygidium than ptychopariids
What is the sicula of graptolites?
conical structure in which the first member of the colony lived
What are stipes and dissepiments?
Stipes are a branch of the theca, it is a stack of thecae built up to form a colony
and
Dissepiments connect stipes
What are thecae?
individual cups in which the zooids lived
What is the aperture?
Terminal ring to a theca where the zooid protruded to filter feed
What is the virgella?
Spine at the end of the sicula
What is the nema?
long extension to the top of the sicula, possibly for attachment to a floating object