Name/Title
AmmoniteEntry/Object ID
2011.57.128Description
Crystal System: Hexagonal System
Description: Phylum: Mollusca
Class: Cephalopoda
Genus: Ammonoidea
Common Name: Ammonite
Age: Jurassic
Location: Unknown
Description: Very large ,thick slab with at least (4) ammonite fossils. (2) are negative immpressions and (2) are positive immpressions. Detail is fairly good. Color is light to dark tan with some black.
Physical Characteristics:
Ammonites (/'æm?na?ts/) are an extinct group of marine invertebrate animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids (i.e. octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species.Ammonites are excellent index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods. Their fossil shells usually take the form of planispirals, although there were some helically-spiraled and non-spiraled forms (known as heteromorphs).The name ammonite, from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder (d. 79 AD. near Pompeii) called fossils of these animals ammonis cornua ("horns of Ammon") because the Egyptian god Ammon (Amun) was typically depicted wearing ram's horns.[1] Often the name of an ammonite genus ends in -ceras, which is Greek (???a?) for "horn".
Fracture: Conchoidal
Genus: Ammonoidea
Grain Size: Fine
Hardness: 3 Calcite
Kingdom: Animalia (Animals)
Luster: Vitreous
Class: Cephalopopda
Phylum: Mollusca
Rock Origin: Terrestrial
Rock Type: Sedimentary
Streak: whiteCollection
Museum Collection of FossilsAcquisition
Accession
2011.57Source or Donor
Museum Collection of FossilsAcquisition Method
Long-term LoanDimensions
Width
20-1/4 inDepth
8 inLength
20-1/2 inLocation
Location
Room
Fossil RoomBuilding
Crater Rock MuseumCategory
Permanent
