Cylindroteuthis Belemnites Mikhailov | Ryazan Region, Russia | SO24

The belemnites are a monophyletic group of superorder status, called the Belemnoidea. There are four orders . The belemnites evolved from nautiloids, which are the basal group of cephalopods. Well-formed belemnite guards can be found in rocks dating from the Mississippian (or Lower Carboniferous).

The belemnites on offer are of Cylindroteuthis and Pachyteuthis genus.  They date from the Callovian era.  In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic and It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian.  They were found in Mikhailov, Ryazan region. Russia.

Cylindroteuthis is a common find from several Jurassic formations.  The most commonly preserved part of the animal is its guard, or rostrum, which was composed of calcite. The guard housed a phragmacone, which allowed Cylindroteuthis to maintain buoyancy in water. Some better-preserved specimens have features similar to modern squid, such as ten arm-like appendages and an ink sac, intact.

Pachyteuthis is a genus of belemnite that lived from the Early Jurassic to the Early Cretaceous and has been found in Asia, Europe and North America. The type species is P. densus.

Name: Cylindroteuthis
Age: Middle Jurassic
Location: Ryazan region, Russia
Dimensions:  109x19 mm / 4.3x0.7 inches
Weight:  51 grams / 1.8 ounces