What is Monoplacophora?
Q: What is Monoplacophora?
A: Monoplacophora is a class of molluscs that have a cap-like shell and live on the bottom of the sea.
Q: When were Monoplacophorans well-known as a fossil group?
A: Monoplacophorans were well-known as a fossil group from the Cambrian to the Devonian.
Q: What was one of the most remarkable modern discoveries of a 'living fossil'?
A: One species was dredged up from the Pacific Ocean off Mexico in 1952, which was found to be a Monoplacophoran given the genus Neopilina. This discovery was one of the most remarkable modern discoveries of a 'living fossil'.
Q: What does "pull of the recent" mean in palaeontology?
A: The term "pull of the recent" in palaeontology refers to all fossil groups having a first and last appearance in the fossil record, but for living species their last appearance is present day, which may be much later than their last appearance as fossils.
Q: How did this discovery extend their time range by 400 million years?
A: The discovery of living monoplacs extended their time range by 400 million years because it showed that they had survived longer than previously thought.
Q: What does Neopilina's anatomy suggest about ancient mollusc ancestors?
A: Neopilina's anatomy suggests that ancient mollusc ancestors had bilateral symmetry and segments, with serial repetition of anatomical structures such as gills and muscles having evolved once in common ancestor chitons and monoplacophorans.
