Microbrachis

Microbrachis ('small arm') is an extinct genus of lepospondyl amphibian from the Carboniferous Kladno Formation of the Czech Republic.
Description.
"Microbrachis" was an elongated, salamander-like creature, about long, with over 40 vertebrae instead of the average 15–26 in its living relatives. It had minute limbs, and probably swam using fish-like lateral body movements. "Microbrachis" probably fed on fresh water plankton such as shrimp. "Microbrachis" was pedomorphic, retaining its larval gills in adulthood. Similar traits are found in the extant axolotl.