Eucritta melanolimnetes ('creature from the black lagoon') is an extinct tetrapod

Tetrapod

Tetrapods are vertebrate animals having four limbs. Amphibians, reptiles, birds and mammals are all tetrapods; even snakes and other limbless reptiles and amphibians are tetrapods by descent. The earliest tetrapods evolved from the lobe-finned fishes in the Devonian...

 from the Carboniferous

Carboniferous

The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 period of Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

. Its name is a homage to the 1954 sci-fi/horror movie Creature from the Black Lagoon

Creature from the Black Lagoon

Creature from the Black Lagoon is a 1954 monster horror film directed by Jack Arnold, and starring Richard Carlson, Julia Adams, Richard Denning, Antonio Moreno, and Whit Bissell. The eponymous creature was played by Ben Chapman on land and Ricou Browning in underwater scenes...

.

Eucritta was about 25 centimetres (9.8 in) long, and displayed mixed tetrapod characteristics, such as an amphibian

Amphibian

Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...

-like skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

 and a reptilian palate

Palate

The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior...

. Its eye sockets were shaped like keyholes, with pointed openings at the front that may have contained a gland of unknown function. This characteristic is also seen in the Loxommatidae

Loxommatidae

Baphetidae is an extinct family of early tetrapods. Baphetids were large labyrinthodont predators of the Late Carboniferous period of Europe. Fragmentary remains from the Early Carboniferous of Canada have been tentatively assigned to the group...

 family, in which Eucritta has been placed. However, its exact phylogenetic position is not known with much certainty due to its mixture of primitive and derived

Derived

In phylogenetics, a derived trait is a trait that is present in an organism, but was absent in the last common ancestor of the group being considered. This may also refer to structures that are not present in an organism, but were present in its ancestors, i.e. traits that have undergone secondary...

 tetrapod characters. The possession of characters seen in baphetids, anthracosaurs, and temnospondyls suggests that these three groups diverged in the Carboniferous rather than earlier, in the Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

.