Gastropoda - Neomesogastropoda and Neogastropoda

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