Balanerpeton is an extinct genus of temnospondyl

Temnospondyli

Temnospondyli is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Cretaceous. Fossils have been found on every continent...

 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...

 from the Early Carboniferous period. It reached approximately 50 cm (20 in) in size .Balanerpeton woodi was discovered by Stanley Wood and is the earliest and most common tetrapod in the East Kirkton Quarry

East Kirkton Quarry

East Kirkton Quarry is a former limestone quarry, now better known as a fossil site known for terrestrial fossils from the fossil-poor "Romer's gap, a 15 million year period at the beginning of the Carboniferous...

 assemblage of terrestrial

Terrestrial animal

Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...

 amphibians in 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...

. Characteristics of Balanerpeton woodi include the presence of large external nares, large interpterygoid vacuities and an ear with a tympanic membrane and rod-like stapes . The morphology of the stapes suggests that the animal was capable of hearing high-frequency sound. B. woodi does not possess lateral line sulci

Sulcus (anatomy)

A sulcus is a depression or fissure in the surface of an organ, especially the brain.-Elsewhere:* anterior interventricular sulcus* calcaneal sulcus* coronal sulcus* gingival sulcus* gluteal sulcus* interlabial sulci...

 or an ossified branchial system. The principal method of respiration was probably buccal

Buccal

Buccal may refer to:* Mouth, a body cavity** Specifically the cheek* Buccal artery...

 (gulping air through mouth) rather than costal

Rib

In vertebrate anatomy, ribs are the long curved bones which form the rib cage. In most vertebrates, ribs surround the chest, enabling the lungs to expand and thus facilitate breathing by expanding the chest cavity. They serve to protect the lungs, heart, and other internal organs of the thorax...

(expanding chest volume to take in air), indicated by the small straight ribs.