Aquilonifer

Aquilonifer spinosus is an extinct species of arthropod from the Silurian period.^[2][3] It is known from a single fossil specimen found in the Wenlock Series Lagerstätte of Herefordshire, England, in rocks about 430 million years old. The 1 cm long specimen is a stem-group mandibulate, not directly related to any living species. The many-legged, eyeless adult has ten unusual tethered appendages, interpreted as juveniles attached to the parent, in a unique form and previously unknown brooding behaviour.^[1]

Aquilonifer Temporal range: Wenlock ~430 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Aquilonifer spinosus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Stem group:	Mandibulata
Genus:	†Aquilonifer Briggs, Siveter, Siveter, Sutton & Legg, 2016[1]
Species:	†A. pinosus
Binomial name
†Aquilonifer pinosus Briggs, Siveter, Siveter, Sutton & Legg, 2016

Studies in 2018 and 2022 recovered Aquilonifer as a possible close relative of Pycnogonida and Marrellomorpha, suggesting that the latter is a paraphyletic group, but this result was considered unexpected by the authors of both studies.^[4][5]

Etymology

"Aquilone" is Italian for "toy kite", and the suffix "–ifer" means "to carry".^[3] "Spinosus" means "spiny" in Latin. Its discoverers have nicknamed it "the kite runner".^[2]