Rhysocaryoxylon madsenii Sakala et Gryc

Plant Fossil Names Registry Number: PFN000385

Act LSID: urn:lsid:plantfossilnames.org:act:385

Authors: J. Sakala & V. Gryc

Rank: species

Reference: Sakala, J. & Gryc, V. (2011): A new species of Rhysocaryoxylon (Juglandaceae) from the Lower Eocene Fur Formation of Mors island (northwest Jutland, Denmark). – Bulletin of the Geological Society of Denmark 59: 45–49.

Page of description: 46

Illustrations or figures: fig. 3


Holotype UF 19079 – 49102, Paleobotany Collections, Florida Museum of Natural History, Gainesville, Florida, USA
Figures: fig. 3

Note: holotype includes also three thin sections (49102tr, 49102tg, 49102rd) housed in the same repository as specimen no. UF 19079 – 49102

Macroscopic description: One silicified piece of fossil wood, dimensions of the analyzed sample 2 × 2 × 3 cm, colour brown-black, interpreted as a fragment of a trunk.

Original diagnosis/description

Heteroxylous semi-ring-porous wood with distinct growth ring boundaries. Vessels are solitary or in radial multiples of 2–5, and can exceed 300 μm in tangential diameter, perforation plates are exclusively simple, tyloses abundant. Rays are 1–5-seriate and heterocellular with body composed of procumbent cells and 1–4 marginal rows of upright cells. Axial parenchyma is reticulate with numerous prismatic crystals both in chambered cells and idioblasts, forming long (up to 12 cells high) vertical chains.


Named for the finder Henrik Madsen.


Paleogene, Eocene
Lower Eocene of the Fur Formation


Ejerslev Moler Pit, Mors island, northwest Jutland

Plant fossil remain

fossil wood


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