Masillastrix

This article relies on a single source. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Masillastrix" – news · newspapers · books · scholar · JSTOR (November 2026) (Learn how and when to remove this message)

Masillastrix Temporal range: Middle Eocene (Lutetian), ~47.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Holotype under different preparation stages, including stomach contents in inset (A)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Strigiformes
Family:	†Protostrigidae (?)
Genus:	†Masillastrix Mayr in Mayr et al., 2026
Species:	†M. blattophaga
Binomial name
†Masillastrix blattophaga Mayr in Mayr et al., 2026

Masillastrix (lit. 'Messel owl') is an extinct genus of stem-owl known from the mid-Eocene (Lutetian age) Messel Pit of Germany. The genus contains a single species, Masillastrix blattophaga, known from a nearly complete postcranial skeleton preserved on a slab and counterslab. This specimen is the first owl fossil with well-preserved feathers from the tail and wings. Masillastrix is the second owl fossil described from the Messel Pit, following Palaeoglaux artophoron. The preserved stomach contents of the Masillastrix specimen reveal an iridescent cockroach, representing both the first instance of an insect as a fossil bird's last meal and the only known instance of an owl—extinct or otherwise—preying on this type of cockroach.

Discovery and naming

The Masillastrix fossil material was discovered by Bruno Behr during an excavation in 2025 at outcrops of the Messel Formation near in Messel, Darmstadt-Dieburg, Germany. The specimen was taken to the Senckenberg Research Institute in Frankfurt, where Behr prepared it, and it is now permanently accessioned as specimen SMF-ME 11964. It consists of a nearly complete skeleton missing most of the skull and the tip of the left forelimb, flattened on two opposing slabs, designated as A and B. Extensive feather traces are preserved around the wings and tail, the first such occurrence in a fossil owl.

In 2026, Gerald Mayr and colleagues described Masillastrix blattophaga as a new genus and species of early owl based on these fossil remains, designating SMF-ME 11964 as the holotype specimen. The generic name, Masillastrix, combines the Latin name for Messel, Masilla, with the Latin strī̆x, meaning 'owl' (also the genus name of earless owls). The specific name, blattophaga, derives from Blatta, a cockroach genus, and the Greek word φᾰγεῖν (phăgeîn), meaning 'to eat'.

Masillastrix is the second fossil owl named from the Messel Pit, following Palaeoglaux artophoron in 1992.

References