Skyttegaardia nagalingumiae Elgorr. et B.A.Atk.

Plant Fossil Names Registry Number: PFN003084

Act LSID: urn:lsid:plantfossilnames.org:act:3084

Authors: A. Elgorriaga & B. A. Atkinson

Rank: species

Genus: Skyttegaardia E.M.Friis, P.R.Crane et K.R.Pedersen

Reference: Elgorriaga, A. & Atkinson, B. A. (2023): Cretaceous pollen cone with three-dimensional preservation sheds light on the morphological evolution of cycads in deep time. – New Phytologist 238(4): 1695–1710., link

Page of description: 1697

Illustrations or figures: figs 1-3

Types

Original diagnosis/description

Pollen cone with helically arranged microsporophylls, central axis of 1 mm diameter and total cone diameter of 2 mm. Microsporophyll stalk region short, up to 420 μm long, with a marked abaxial keel, width ranges from 40 up to 600 μm. Sterile distal extension measuring up to 100 μm in width and 1200–1800 μm in length. Pollen sacs with thick uniseriate walls, subcircular to elliptical in outline, measuring 200–300 μm wide and 400–450 μm long. Pollen measuring up to 14–20 μm long on its major axis, with foveolate exine surface. Mucilage canals measuring 50–150 μm in diameter. Transfusion tracheids from distal region of microsporophyll abundant, with reticulate to pitted secondary wall thickenings.

Etymology

Named in honour of the late Dr. Nathalie Nagalingum (California Academy of Sciences) whose contributions have greatly improved our understanding on the evolution and diversification of cycads.

Stratigraphy

Cretaceous, Upper Cretaceous, Campanian
Holz Shale Member, Ladd Formation,Late Cretaceous. Early Campanian.

Locality

United States
Silverado Canyon, Santa Ana Mountains, CA, USA (lat. 33°44043′′N, long. 117°38037′′W)