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
What is the rhabdosome?
whole graptoloid’s skeleton, which may consist of one or several stipes
What are the endofaunal habits for bivales?
Burrowing
Quasi-infaunal (partially or fully buried)
Interstitial
What would the nature of the substrate been like for endofaunal bivalves?
Soft bottom (burrowing)
Initial pediculate attachment to hard bottom + partial burying in soft bottom (quasi)
Attachment to hard bottom in voids of uncompact sediment (Inter)
What is the changning habit for epifaunal lophophorates?
Hard bottom
Detached but support by hard or soft bottom
Soft/ hard bottom plants
Transition to recumbence/ detachment
What are the characteristics of infaunal shallow burrower bivalves?
Equivalved
Adductor muscles equal size
Strong external ornament
What is an example of an infaunal shallow burrower bivalve?
Glycimeris
What are the characteristics of infaunal deep burrowing bivalves?
Elongate valves
Lack teeth
Permanent gape
Marked pallial sinus
What is an example of a deep infaunal burrower bivalve?
Mya
What are the characteristics of epifaunal with byssus bivalves?
Elongate valve with flat ventral surface
Reduced anterior valve and anterior muscle scar
Attached by thread byssus
What is an example of an epifaunal with byssus bivalve?
Mytilus
What are the characteristics of epifaunal with cementation bivalve?
Markedly different shaped valves
Crenulated commissure (wavy)
Large single adductor muscle
What is an example of an epifaunal with cementation bivalve?
Ostrea
What are the characteristics of unattached recumbent bivalves?
Spines for anchorage/ prevent sinking into sediment
Horn shape
What is an example of an unattached recumbent bivalve?
Gryphaea
What are the characteristics of simmer bivalves?
Valves dissimilar shape and size
Very large single adductor muscles
Hinge line extended as ears
What is an example of a swimmer bivalve?
Pecten
What are the characteristics of bore and cavity dweller bivalves?
Elongated cylindrical shell
Strong sharp external ornament
What will ichnofabric index indicate?
How much burrowing has occurred in a rock
What will a heavily bioturbated rock look like?
No rock structure (laminae) will remain
What is ISOW?
Iceland Scotland Overflow Water
What are the three key XFR ratios?
Calcium to Titanium
Zircon to Rubidium
Potassium to Titanium
What does the calcium to titanium ratio show?
distribution/ source of calcium carbonate (calcium) to titanium (silica-rich)
What does a high Ca/Ti ratio mean?
More calcium carbonate production from increased phytoplankton production
What is Zircon an indicator of?
due to being more resistant usually coarser
What does Zircon to Rubidium ratio show?
Coarser or finer sediment.
Zircon indicates coarser and thus stronger water currents
What does the K/Ti ratio indicate?
Balance between Icelandic sediments (K) and continental sources from Greenland (Ti)
