Brontoscorpio

Brontoscorpio is an extinct genus of possible scorpion that lived in the Early Devonian. Remains of the only known species, Brontoscorpio anglicus, were discovered in the St. Maughan's Formation,^[1][2] Lochkovian-aged (previously also considered as late Silurian)^[3] sandstone from Trimpley, Worcestershire.^[3]

Brontoscorpio Temporal range: Lochkovian 416–412.3 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Size estimation of Brontoscorpio anglicus, with the only evident region (free finger of right pedipalp) highlighted in dark grey
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Scorpiones
Family:	incertae sedis
Genus:	†Brontoscorpio Kjellesvig-Waering, 1972
Species:	†B. anglicus
Binomial name
†Brontoscorpio anglicus Kjellesvig-Waering, 1972

Taxonomic history

The species was described on the basis of an incomplete single free finger of a right pedipalp (In31405), almost 10 cm (3.9 in) long.^[3][4] The complete animal is estimated to have been 77.2–91.5 cm (2.5–3.0 ft) long for females and 86.2–94 cm (2.8–3.1 ft) long for males,^[3] possibly making Brontoscorpio one of the largest known scorpions. The species is characterized by the presence of single condyle and row of thick tubercles on the pedipalp free finger.^[3] However, its identity as a scorpion should be treated with caution due to the fragmentary known material of Brontoscorpio and the fact that chelate appendages are also found in other groups of arthropods,^[5] and Braddy (2024) suggested that Brontoscorpio might represent a dactylus of a crustacean instead.^[6]

Ecology

The remains were found in terrestrial sediments, showing evidence of Brontoscorpio being terrestrial. Brontoscorpio may have gone ashore to escape predation, but due to its size, it would have had difficulty supporting its weight on land and likely lived a primarily aquatic life.^[7]