Amiidae

Bowfin ( Amia calva )

• North America, Europe, Asia, South America, Africa

The Amiidae are a family of primitive bony fish that is with the exception of the North American Bald Hecht ( Amia calva ) extinct. In the upper Mesozoic, the family came up with numerous species and genera in Europe and other continents, especially in the northern hemisphere before. Most Amiidae were freshwater fish, but there were also some marine representatives. The last European representatives were before 48-40 million years ago in the lutetium ( Eocene ) and are detected from the Hessian Messel Pit and the sachsenanhaltinischen Geiseltal.

Features

The Amiidae are elongated, almost round in cross-section predators. The back fin of the present-day Kahl pike and some fossil forms is long, takes up more than half the body length and is the main driving element. However, there were also numerous genera with short dorsal fin.

The Amiidae show a pattern of primitive and advanced features. Thus, their caudal fin is short and externally almost symmetrical and rounded or forked, but the tail fin skeleton heterocercal. The neural arches of the vertebrae of the tail are not converted to Uroneuralia. The number of Urodermalia is two or less. The ratio of fin -makers and Hypuralia in the caudal skeleton is approximately 1:1.

In the upper jaw only a single Supramaxillare and no supraoccipital place in the skull. The premaxilla is not protaktil ( vorstreckbar ), but firmly attached to the skull. On the lower side of the gill region, there are some Branchiostegalstrahlen. In addition, it is protected by a large red - bone plate ( Gularia ). Similar to almost all True Bony Fishes ( Teleostei ) have the Amiidae with the symplectic an additional ventral element in the temporomandibular joint. The articulation for the lower jaw is formed together with the quadrate, but is shaped differently than that of the Teleostei. The vertebral anatomy is primitive, the vertebral bodies never hollowed back. The scales are without Ganoinschicht and no longer orthorhombic but cycloid.

Outer systematics

The Amiidae form the order of arc -finned fishes ( Amiiformes ) with three other extinct families from the Mesozoic Era, the Caturidae, the Liodesmidae and the Asian Sinamiidae. The three families lived mostly in the sea, while the Amiidae are freshwater residents mainly.

Inside systematics

• Family Amiidae Subfamily Amiinae ( Upper Cretaceous to present) Amia
• † Cyclurus
• † Pseudamiatus

• † Amiopsis

• † Solnhofenamia

• † Calamopleurus
• † Maliamia
• † Melvius
• † Pachyamia
• † Vida Lamia

• † Nipponamia