Nautiloid

Object/Artifact

-

Crater Rock Museum

Name/Title

Nautiloid

Entry/Object ID

78.57.168

Description

Crystal System: Hexagonal System Description: Phylum: Mollusca Class: Cephalopoda Subclass:Nautiloid Common Name: Chambered Nautiloid Age: Upper Cretaceous Location: Black Hills, South Dakota Description: One Nautiloid which is the oldest of the cephalopods, showing coiled, chambered shell. Physical Characteristics: Nautiloids are among the group of animals known as cephalopods, an advanced class of mollusks which also includes ammonoids, belemnites and modern coleoids such as octopus and squid. Other mollusks include gastropods, scaphopods and pelecypods. Traditionally, the most common classification of the cephalopods has been a three-fold division (by Bather, 1888), into the nautiloids, ammonoids, and coleoids. This article is about nautiloids in that broad sense, sometimes called Nautiloidea sensu lato. Cladistically speaking, nautiloids are a paraphyletic assemblage united by shared primitive (plesiomorphic) features not found in derived cephalopods. In other words, they are a grade group that is thought to have given rise to both ammonoids and coleoids, and are defined by the exclusion of both those descendent groups. Both ammonoids and coleoids have traditionally been assumed to have descended from bactritids, which in turn arose from straight-shelled orthocerid nautiloids. 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: white

Collection

Fossil Collection

Acquisition

Accession

78.57

Source or Donor

Delmar Smith Fossil Collection

Acquisition Method

Donation

Dimensions

Width

3 in

Depth

2-1/2 in

Length

4 in

Location

Location

Container

Right

Drawer

2nd Shelf

Shelf

Right

Cabinet

Case # 2

Wall

West

Room

Fossil Room

Building

Crater Rock Museum

Category

Permanent