Upper Jurassic record of Polyphylloseris (Egypt, Northern Sinai)

Abstract

Genus Polyphylloseris is a scleractinian colonial coral that has been established by d'Orbigny (1849 )f rom the Neocomian of Yonne, France. The genus is characterized by having elevated domal calices that are mammillar or cra- terlike in shape and with porous confluent septa. Columella is absentor rudimentary, and the lower surface ofthe corallumis covered with a thick and wrinkled holotheca. Specimens having the above-mentioned characteristics have beencollect- ed from the Upper Jurassic Arousiah Member of the Masajid Formation (Callovian-Oxfordian) of Gebel Maghara, Northern Sinai, Egypt. They are characterized by having a cupolate colonial form and porous pennulate septa which reach 40-50 in number. Based on these characters and other characters such as density of septa, height, and width of mammillar calices, the studied material is attributed to a new species named Polyphylloseris magharensis .T he new species is a first undoubted record of Polyphylloseris in the Jurassic. Previously recorded undoubted ages of the genus are Early and Late Cretaceous. The fewer number of septa and the smaller-sized and closer mammillar calices allow differentia- tion of the species from other species such as Polyphylloseris icaunensis d'Orbigny and Polyphylloseris convexa