First discovery of avian egg and bone remains (Presbyornithidae) from the Gour Lazib (Eocene, Algeria)

Numerous avian eggshells and one well-preserved small ovoid-shaped egg (32 × 28 mm) were collected from three localities in the Gour Lazib area (HGL10, HGL51 and HGL62), western Algeria from the Glib Zegdou Formation dated from the late early or early middle Eocene. This material was associated with a rich vertebrate fauna. The study of the eggshells using microscopies (PLM and SEM) led to attribute them to neognathous birds. They are characterized by a thin shell (less than 0.5 mm thick) with a prismatic trilaminate microstructure. The occurrence of an avian carpometacarpus belonging to the Presbyornithidae from HGL50, which is located 1 m below the HGL 51 level, suggests that the egg remains may be referred to this bird family, which is so far unknown in the Palaeogene of the Afro-Arabian continent.