| Lituites | |
|---|---|
 | |
| A specimen ofLituites littuus from theVästergötland Province ofSweden | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | †Tarphycerida |
| Family: | †Lituitidae |
| Genus: | †Lituites |
| Species | |
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Lituites is an extinctnautiloid genus from theMiddle Ordovician and type for theLituitidae (atarphycerid family) that in some more recenttaxonomies has been classified with theorthocerids and listed under the orderLituitida. Fossils have been found inNew York,Argentina,Norway,Sweden,Estonia, andChina.
Lituites produced a shell with a planospirally coiled juvenile portion at the apex, reflective of its tarphycerid ancestry, followed by a long, moderately expanding, generally straight,orthoconic adult section with a subdorsalsiphuncle connecting the chambers. The adult body chamber may equal or exceed the length of the chambered part of the orthoconic section. The mature aperture has a pair of pronouncedventrolaterallappets and a similar but shorter pair ofdorsolateral lappets.
Lituites gives its name to the term "lituiticone" which refers to a shell that is coiled in the early growth stage and later becomes uncoiled.