Monday, May 19, 2008

Gastropoda - Neomesogastropoda and Neogastropoda

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Here follows the continuation of yesterday's Caenogastropoda. Subject will be the Neomesogastropoda that have a typically large larval shell, characteristic adult shells and a large foot. Ordovician - today. Also I will review the Neogastropoda.

Natica
  • bellied shell
  • holostome Aperture
  • "Propodien"
  • drilling in sediment and sucking out mussels - round holes caused by acid
  • carnivor
  • lower Cretaceous - today
  • shallow to deep sea
Cypraea
  • Kauri-Snail
  • large final whorl
  • convolute growth
  • herbivor grazing
  • marine
  • tropical - subtropical
  • upper Cretaceous - today
Lamellaria
  • mantle over shell
  • acid from mantle
  • secondary mineralisation of shell
Calyptraea
  • suspension feeder
  • hemisessile
  • consecutive Hermaphrodism
  • upper Cretaceous - today
  • parasitic, coprophagous
  • division into Protoconch and Teleconch
Cassis
  • helmet snail
  • feeds on Echinoderms
  • typical Radula for "drilling" holes
Tonna
  • feeds on sea cucumbers
  • short and wide siphonal channel
  • larva has thick, organic shell and is planctic
Cassis and Tonna - thorns = protection against sinking into sediment

Ficus
  • today: deep sea and shelf
  • relict of the upper Cretaceous
  • vermicular food
  • very long trunk
  • marine
  • subtropical - tropical
  • fossorial for food
Since Turonian/Maastrichian development to Neogastropoda
  • Aperture siphonostome
  • long siphonal channel
  • Ordovician - today
  • carnivor since upper Cretaceous (?)
Buccinum
  • final whorl large and bellied-rounded
  • Aperture wide with short, cut-out siphonal channel
  • carnivor
  • upper Cretaceous - today
  • tastes good with pepper and boiled in sea water
Melongena
  • brackish
  • feeds on mussels
  • good facies indicator
  • Caribbean, Paratethys
  • Radula: 3 teeth per row (evolutionary trend)
Syrinx
  • largest, shell-carrying snail
  • tropical Australia
  • max. 90 cm!
  • carnivor
Nassarius
  • tropical - subtropical
  • Estuary
  • dug in, agile
  • carnivor
  • 1 to 2 cm
  • no larval stage
  • mud flats
Conus
  • highly toxic!
  • carnivor, feeds on fish
  • transformed Radula tooth
  • Palaeocene - today
  • short Columella
  • long and thin Aperture
  • toxogloss
  • marine, tropical
Terebra
  • toxogloss, 2 teeth
  • vermicular food
  • digs into soft sediment
  • may be confused with Cerithium!
Turris
  • newel-like shell
  • toxogloss
  • "anal sinus"
  • Cretaceous - today
  • down to deep sea, Artic, tropical
  • 2. siphonal exit
  • typical Asthetics
Cancellaria
  • parasitic on sharks
  • tropical
  • upper Cretaceous
Mitra
  • thick shell
  • tropical shallow seas
  • might live in sediment
Voluta
  • no planctic Ontogeny
  • giant Protoconch
  • often tabby appearance
Murex
  • shell spheroidal - egg-shaped
  • thorny extensions
  • intertidal - soft sediment
  • carnivor
  • "purple snail"
  • Miocene - today
  • easy to recognise
Corallophila
  • parasitic in Corals
  • sessile
  • etches itself into Corals
  • Indo-Pacific
  • planctotrophic
Next: Heterostropha

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