Extinct family Chaerilobuthidae from Mid-Cretaceous Burmese amber with 16 species are now a part of the extant family Pseudochactidae

 

In a recent article, Qiang Xuan and co-workers have analyzed the taxa in the extinct family Chaerilobuthidae Lourenço and Beigel, 2011. This family originally consisted of 3 genera and 16 species. All taxa are based on fossil specimens found in Mid-Cretaceous Burmese amber.

The authors conclude that the family Chaerilobuthidae should change status to subfamily (Chaerilobuthinae) and placed in the extant family Pseudochactidae Gromov, 1998. The two extinct genera Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus Lourenço and Beigel, 2011 which contains 16 species (all extinct).

Chaerilobuthinae with its taxa is now listed in The Scorpion Files for Pseudochactidae, but are not included in the count of number of taxa which only includes extant taxa.

Abstract:
The extinct scorpion family Chaerilobuthidae Lourenço and Beigel, 2011, endemic to Burmese amber, was initially established due to its unique pedipalp trichobothrial pattern related to the Type A and Type B patterns of families Buthidae C.L. Koch, 1837 and Chaerilidae Pocock, 1893, respectively. The present contribution describes 11 new specimens, representing seven species of Chaerilobuthidae from Mid-Cretaceous Burmese amber, revealing their morphology using various imaging technologies. A revised diagnosis of Chaerilobuthus Lourenço and Beigel, 2011 is provided based on new morphological characters of the carapace, ocelli, chelicera, pedipalp trichobothria, coxapophyses, and leg tarsi. The other two genera of Chaerilobuthidae, Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus based on a reassessment of their morphological characters and morphometric analysis, creating Chaerilobuthus brigittemuellerae (Lourenço and Velten, 2020), comb. nov. and Chaerilobuthus schmidti (Lourenço and Velten, 2024), comb. nov.. The systematic position of Chaerilobuthidae is clarified based on phylogenetic analyses of an updated morphological character matrix for Pseudochactidae Gromov, 1998, an extant family in Asia. Phylogenetic analysis placed Chaerilobuthidae sister to the pseudochactid subfamily Vietbocapinae Lourenço, 2012, justifying its transfer to Pseudochactidae, as Chaerilobuthinae Lourenço and Beigel, 2011, stat. nov.. This discovery confirms that Pseudochactidae date back 100 Mya and contributes to understanding the origin and evolutionary history of this relictual family.

Reference:
Xuan Q, Prendini L, Engel MS, Cai C, Huang D. Extinct scorpion family Chaerilobuthidae from Mid-Cretaceous Burmese amber reinterpreted as subfamily of extant family Pseudochactidae (Chelicerata: Scorpiones). Zoological Journal of the Linnean Society. 2025;203(1):zlae169. [Subscription required for full text]

Thanks to Gerard for informing me about this article!

Family Pseudochachtidae

New fossil scorpion taxa

 

I have learned about two new articles on scorpion fossil taxa. The Scorpion Files only includes extant taxa, but here are the new fossil taxa reported in the two articles cited below.

New family:

Protochactidae Lourenço, Magnani & Stockar, 2022

New genus:

Protochactas Lourenço, Magnani & Stockar, 2022

New species:

Protochactas furreri Lourenço, Magnani & Stockar, 2022 (Limestone, Southern Alps)

Chaerilobuthus brandti Lourenço, 2022 (Amber, Myanmar)

Abstract:

Paper 1:
One new family, genus, and species of fossil scorpion are described from the Meride Limestone (Ladinian, Middle Triassic) of Monte San Giorgio (Southern Alps). This new discovery brings further evidence for the recovery of terrestrial forms of scorpions, following the Late-Permian mass extinction. The new fossil family proposed at present can, once again, be classified within extant familial groups; in this case the superfamily Chactoidea (sensu Lourenço). These results reinforce the proposition that modern scorpions may belong to lineages present at least for 240 Myr.

Paper 2:
A further new species of fossil scorpion belonging to the genus Chaerilobuthus Lourenço & Beigel, 2011 is described from Early Cretaceous Burmite. Chaerilobuthus brandti Lourenço sp. n., is the 12th species to be described for this genus confirming its speciose character. The new species equally shows quite distinct characters when compared to the previous known species, confirming therefore the existence of an important morphological variability within Chaerilobuthus.

References:

Paper 1:
Magnani F, Stockar R, Lourenço WR. A new family, genus and species of fossil scorpion from the Meride Limestone (Middle Triassic) of Monte San Giorgio (Switzerland). Faunitaxys. 2022;10(24):1-7. [Open Access]

Paper 2:
Lourenço WR, Velten J. The remarkable variability of the genus Chaerilobuthus Lourenço & Beigel, 2011 (Scorpiones: Chaerilobuthidae) and description of a new species from Early Cretaceous Burmite. Faunitaxys. 2022;10(10):1-6. [Open Access]

Thanks to Nicolas Machiavel for informing me about these two articles!

A new scorpion fossil from cretaceous amber found in Myanmar (Burma)

Wilson Lourenco and Alex Beigel have published a new family, genus and species of fossil scorpions based on a specimen found in cretaceous amber from Burma.

Chaerilobuthidae Lourenco & Beigel, 2011
Chaerilobuthus Lourenco & Beigel, 2011
Chaerilobuthus complexus Lourenco & Beigel, 2011

Abstract:
A fossil scorpion belonging to a new family, genus and species, Chaerilobuthus complexus gen. n., sp. n., is described from Cretaceous amber of Myanmar (Burma). This is the third species and the fourth scorpion specimen to have been found and described from Burmese amber. The new family seems quite distinct from the family Archaeobuthidae Lourenco, 2001 described from Cretaceous amber of Lebanon.

Reference:
Lourenço WR, Beigel A. A new scorpion fossil from the Cretaceous amber of Myanmar (Burma). New phylogenetic implications. Comptes Rendus Palevol. 2011;10(8):635-9. [subscription required for fulltext]

Thanks to Professor Lourenco for sending me this paper!