Megataxa

New genera, species and occurrences of Goniasteridae (Valvatida, Asteroidea) from New Caledonia

CHRISTOPHER L. MAH — 2026-01-06

The Goniasteridae is the most diverse family of living asteroids, containing the greatest number of described genera and species. Herein, 28 new species, 3 new genera and 19 new records are described from New Caledonia, almost entirely from deep-sea settings (>200 m). An accounting of the goniasterid fauna shows a total of over 70 species, in 38 genera from 3 subfamilies. If this is considered relative to the total known number of goniasterid species, this accounts for nearly 20% of total species and 46% of genera are represented from this region suggesting that the goniasterid diversity in this area is relatively high.

New taxa of Mesophotic Asteroidea from Ashmore Reef, Western Australia

CHRISTOPHER L. MAH — 2026-01-06

We report on 27 asteroid specimens collected by the RV Falkor, using the ROV SuBastian, from mesophotic depths on Ashmore Reef in Western Australia, 2021. Of the total, 10 new species were collected, 9 of which are described here. Sixteen species were new occurrences for Western Australia. One additional shallow water species was observed at mesophotic depths but not collected. Each collected specimen was identified as a different species. In the Valvatida, this included Goniasteridae (n=9), Mithrodiidae (n=1), Ophidiasteridae (n=4), Asterinidae (n=3), Asterodiscididae (n=2), Oreasteridae (n=2), Podosphaerasteridae (n=1), and the Echinasteridae (n=3). Also present were two non-valvatidan groups, a brisingid from the Forcipulatacea and a new species of pterasterid in the genus Euretaster from the Velatida. Consistent with other accounts of mesophotic asteroid distribution, some of the species observed here, such as the goniasterid Churaumiastra hoshi Mah et al. 2024 have been found to be widely distributed across the Indo-Pacific.

Zigzags in the White Sand Belt: A new, highly divergent lineage of sand-swimmer skink from Madagascar (Squamata: Scincidae)

AURÉLIEN MIRALLES — 2026-02-23

The present work reports on the discovery of a new sand swimming lizard (Scincidae: Scincinae) in Madagascar. This limbless and eyeless skink was found during fieldwork in the northern part of the “great white sand belt”, a series of patchy white sand areas encircling the island’s western sedimentary basins. The new taxon shows a distinctive combination of derived morphological traits (miniaturized, limbless, elongated body, with absent or scale-covered eyes and ear openings, and a reduced head scale pattern) reminiscent of other Malagasy fossorial skinks adapted to sandy habitats (e.g. Voeltzkowia, Grandidierina and some Paracontias). Phylogenetic analyses based on two datasets (multilocus DNA from Sanger sequencing and genome-wide DNA sequences derived from double-digest Restriction Associated DNA [ddRAD]) reveal a highly divergent phylogenetic position of this taxon and, given its distinct morphology, justify its description as a new species in a new genus, Zig zag gen. nov. & sp. nov. This marks the first genuine field discovery of a new genus of Scincidae in Madagascar since the 19th century, i.e., the discovery of a formerly unknown deep clade rather than an identification (and split) from an already recognized genus. Our results also shed light on the ancient evolutionary history of this taxon and its sister clade, Paracontias. Finally, the present work explores the factors that may explain why ecosystems characterized by white sand substrates, an ecosystem often neglected in biodiversity research, but present in various regions of the globe (e.g., Florida sand scrub, South American WS savannah, Indonesian Keranga) have seemingly so frequently promoted the convergent evolution of fossorial squamates.