Acrochordiceras is a Middle Triassic

Middle Triassic

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

 ammonoid cephalopod belonging to the ceratitid

Ceratitida

The Ceratitida is an order that contains almost all ammonoid cephalopod genera from the Triassic as well as ancestral forms from the Upper Permian, the exception being the phylloceratids which gave rise to the great diversity of post Triassic ammonites....

 family Acrochordiceratidae, included in the superfamily Ceratitaceae

Ceratitaceae

The Ceratitaceae is a superfamily in the ammonoid cephalopod order Ceratitida characterised in general by highly ornamented or tuberculate shells with ceratitic sutures that may become goniatitic or ammonitic s some offshoots....

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The shell of Acrochordiceras, as with the family, is more or less involute with strong, almost transverse, ribs that cross the arched venter uninterrupted. The ventral lobe is bifid. The first lateral lobe is larger than the other and is multi-pronged. Prongs on subsequent smaller lobes are less developed and saddles are small and rounded.

Acrochordiceras was described by Hyatt in 1877 and is known from Eurasia

Eurasia

Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

, Timur

Timur

Timur , historically known as Tamerlane in English , was a 14th-century conqueror of West, South and Central Asia, and the founder of the Timurid dynasty in Central Asia, and great-great-grandfather of Babur, the founder of the Mughal Dynasty, which survived as the Mughal Empire in India until...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

 and Nevada

Nevada

Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

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