Post

Welcome a new family of #birds, the Caribbean cave rails, Nesotrochidae! They were—surprisingly—the sisters of NZ adzebills, all sadly extinct. New #OpenAccess paper out in Avian #Systematics w Gerald Mayr, Chen Guangji & Feng Shaohong: www.avespress.com/uploads/down... 🧵 #ornithology #taxonomy 🧪🪶

So what's new and what was known? In 2021, Jessica Oswald & colleagues managed to extract ancient DNA from a Haitian Cave Rail (Nesotrochis steganinos) and, analysing #mitochondrial DNA, found they were not #rails(!) but more closely related to flufftails and adzebills: doi.org/10.1098/rsbl...

This was a super cool study, but the exact placement of cave rails was unresolved: they could be basal to flufftails & adzebills, sister to flufftails (best supported) or to adzebills—yielding wildly different classification options. Expanding Sarothruridae (flufftails) or Aptornithidae (adzebills)?

The phylogenetic analyses bugged me a little, though, as I thought more rigorous DNA substitution model testing and partitioning (and RY-coding of third-codon positions) might provide more clarity... So I'd better test it! We used the same dataset—except data for two species were unavailable—

Dated Bayesian analyses of 9,615 base pairs coding mitochondrial sequence, in 16 partitions w optimised substitution models, didn't result in the unresolved polytomy of Oswald et al. (2021). Neither was Nesotrochis sister with Sarothruridae, but split as sister from Aptornithidae 37 Mya!

This fully supported topology presents three options: merge family Aptornithidae (adzebills) with (1) Nesotrochis or (2) that + current family Sarothruridae (flufftails)—or (3) award the cave rails family status as Nesotrochidae. #1–2 seem unreasonable given the marked distinctness of adzebills...

...so we described Nesotrochidae fam. nov., the cave rail family! They are (were) distinguished by a number of osteological characters, not least that the humerus has a large and ventrally protruding processus flexorius. Voilá: Nesotrochidae Stervander, Chen, Feng & Mayr, 2025!