#2774 - Zeacolpus (Leptocolpus) semiconcavus - Tower Snail
Originally described as Turritella semiconcava, in 1911. Also known as Leptocolpus semiconcavus. I'm unclear on whether that's the generally accepted binomial, these days.
The oldest of the Zeocolpus species, found in the Whangaloan deposits. Unfortunately the Whangaloan rocks are of uncertain age, since they lack the necessary index fossils to exactly place them. Somewhere over the end of the Cretaceous and start of the Triassic, anyway.
The genus is mostly known from New Zealand, but there's one known from the Eocene of Western Australia. Several have been moved to the genus Stiracolpus.
Turretellids are filter feeders; somewhat unusual among gastropods. A few fossils of Z. taranakiensis have been collected with the last whorl containing many juvenile shells. This indicates that the species was ovoviviparous.
University of Otago Geology Museum, Dunedin, Aotearoa New Zealand.
