Hanschaubiana, n. gen., from the Eocene of Egypt, with evidence of supplementary life cycles in Foraminifera
Boukhary, professor Mohamed; Yasmine Hussein-Kamel; AHMED ABD EL NABY;
Abstract
ABSTRACT: Hanschaubiana new genus with the type species Assilina nili De La Harpe 1883 is described and photographed
and its systematic position revised. The species was established byDe LaHarpe in 1883 and assigned to the genus
Assilina from an outcrop of the Early Eocene Thebes Formation at Gebel Deir, near Esna in the Nile Valley. The form belongs
to the family Nummulitidae, but it is neither an Assilina nor an Operculina, because it possesses transverse
trabecules and does not have alar prolongations. The population consists of 3 morphic forms: agamonts (B Form) and
gamonts (AForm), the A-form includes two subgroups:A1 generation, which represents smallmegalospheric tests, andA2
generation, whose test sizes are comparable with the juvenile B-form but with large proloculus and they are also
megalospheric tests. Such variation in the A-form is evidence for a three-phase life cycle (trimorphism) that includes:
agamonts (B- trimorphic form), gamonts (A1 trimorphic Form), and gamonts (A2 trimorphic Form).Adifferential diagnosis
between the new taxon and allied taxa is provided. The new taxon is found associated with
and its systematic position revised. The species was established byDe LaHarpe in 1883 and assigned to the genus
Assilina from an outcrop of the Early Eocene Thebes Formation at Gebel Deir, near Esna in the Nile Valley. The form belongs
to the family Nummulitidae, but it is neither an Assilina nor an Operculina, because it possesses transverse
trabecules and does not have alar prolongations. The population consists of 3 morphic forms: agamonts (B Form) and
gamonts (AForm), the A-form includes two subgroups:A1 generation, which represents smallmegalospheric tests, andA2
generation, whose test sizes are comparable with the juvenile B-form but with large proloculus and they are also
megalospheric tests. Such variation in the A-form is evidence for a three-phase life cycle (trimorphism) that includes:
agamonts (B- trimorphic form), gamonts (A1 trimorphic Form), and gamonts (A2 trimorphic Form).Adifferential diagnosis
between the new taxon and allied taxa is provided. The new taxon is found associated with
Other data
| Title | Hanschaubiana, n. gen., from the Eocene of Egypt, with evidence of supplementary life cycles in Foraminifera | Authors | Boukhary, professor Mohamed ; Yasmine Hussein-Kamel ; AHMED ABD EL NABY | Issue Date | 2013 | Journal | micropaleontology, vol. 59, nos. 2–3, pp. 95–102, 2013 95 |
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