The Reticulated Siren was first formally described in 2018. It is one of the largest extant amphibians, with adult lengths of approximately 40-60 cm (16-24 inches).
Graham SP, Kline R, Steen DA, Kelehear C (2018) Description of an extant salamander from the Gulf Coastal Plain of North America: The Reticulated Siren, Siren reticulata. PLoS ONE 13(12): e0207460. https://doi.org/10.1371/journal.pone.0207460
Elbein, A. (2018) A Salamander of Legend Emerges From Southern Swamps. New York Times, Dec. 14, 2018. https://www.nytimes.com/2018/12/14/science/salamander-reticulated-siren.html.