Macrofossils: Molluscs and brachiopods Flashcards
What clade are Brachiopods in?
Lophotrochozoans
What is the purpose of the brachiopod pedicle valve?
The overlap that contains the pedicle foramen (hole on the overlap), a fleshy stalk that attaches most brachiopods to the sea floor
Where are brachiopods found?
Cryptic and deepwater habitats
What are brachiopods the sister group to?
Bryozoa
What are brachiopods?
Twin valve shellfish that filter feed. Have a tabular structure to attach to the substrate. Top and bottom shell are different sizes.
Which valve does not contain the pedicle foramen?
Brachial valve
What organ do brachiopods use for filter feeding?
Lophophore
What are Linguliformea?
A subphylum of inarticulate brachiopods
What characterises a mollusc?
The mantle, a fold of skin covering the dorsal surface to protect the gills in the mantle cavity. The outer surface secretes the shell.
What groups are included in the Mollusc phylum?
Ammonoids, cephalopods, gastopods
Where are modern molluscs found?
All depths of water, salt water and fresh water, land.
What do molluscs typically have?
Unsegmented, calcium carbonate shells, a head with sensory organs and a radula (feeding organ), foot (sole-like structure), mantle.
What happened to molluscs (esp. Bivalvia) and brachiopods are the P-T extinction?
Evolutionary arms race that led to bivalves becoming main filter feeder on the sea floor
What can disarticulated shells be used for?
As a younging indicator
What is the name of the separate shell of a cephalopod?
Phramocone
