Herpetological results of Francisco Newton’s Zoological Expedition to Angola (1903 – 1906): a taxonomic revision and new records of a forgotten collection Author Santos, Bruna S. Author Marques, Mariana P. 0000-0002-1712-2632 mptlmarques@gmail.com Author Bauer, Aaron M. 0000-0001-6839-8025 aaron.bauer@villanova.edu Author Ceríaco, Luis M. P. 0000-0002-3798-2664 brunascesantos@gmail.com text Zootaxa 2021 2021-09-03 5028 1 1 80 http://zoobank.org/c678f0fe-1b62-4f34-8a66-449cf9806b50 journal article 10.11646/zootaxa.5028.1.1 1175-5326 5453967 C678F0FE-1B62-4F34-8A66-449CF9806B50 Bitis ( Calechidna ) caudalis (Smith, 1839) Material ( one specimen ): One adult specimen (MHNCUP/REP 322, formerly UP-MHNFCP-094977; Fig. S55 ), collected from Mossâmedes [=Moçâmedes] [-15.20000º, 12.15000º, 24 m a.s.l. ] Namibe Province , in 1905 . Comments: Bitis caudalis is commonly found in arid western regions of southern Africa, with southern Angola as its northern distribution limit ( Branch 2018 ; Marques et al. 2018 ). It is an arenicolous species that belongs to the dwarf adders subgenus, Calechidna , endemic to southern Africa ( Barlow et al. 2019 ). The extant specimen is within the expected range for B. caudalis , but as Ferreira did not properly study the specimens from the last part of Newton’s Expedition, it was not cited or identified. Recently, Barlow et al. (2019) recovered two mitochondrial lineages of B. caudalis which they treated as two different taxa. The limited sampling by the authors did not yield firm conclusions, but showcased the need for further studies, given the apparent cryptic nature of B. caudalis . In addition, no Angolan material was evaluated.A detailed taxonomic revision of the case is being prepared by Ceríaco et al. (in prep). This specimen appears to be relatively hornless, a characteristic that seems to be common in this species ( Spawls & Branch 2020 ; Ceríaco & Marques in press ).