Pseudoanacardium peruvianum (E.W.Berry) Manchester et Balmaki

Plant Fossil Names Registry Number: PFN000446

Act LSID: urn:lsid:plantfossilnames.org:act:446

Authors: S. R. Manchester & B. Balmaki

Rank: species

Basionym: Anacardium peruvianum E.W.Berry

Genus: Pseudoanacardium Manchester et Balmaki

Reference: Manchester, S. R. & Balmaki, B. (2018): Spiny fruits revealed by nano-CT scanning: Pseudoanacardium peruvianum (Berry) gen. et comb. nov. from the early Oligocene Belén flora of Peru. – Acta Palaeobotanica 51(1): 41–48.

Page of description: 42

Illustrations or figures: pls 1, 2

Types

Original diagnosis/description

Nuts reniform in shape, with a thick shell which is missing in a good many of the specimens, but is more or less preserved in several. The surface of the latter show the same faint oblique markings due to the underlying fibrous acrid secretory layer, exactly as in the nuts of Anacardium occidentale, and there is exactly the same wrinkling of the outer coat in the region of the sinus as in the recent species. Where the outer ligneous coat has rotted before silicification, or been subsequently abraded, the inner coat shows identical oblique channelings parallel with the lower margin of the nut exactly
as is shown by the secretory layer of the modern nut. The seed is somewhat bean-shaped, about twice as long as its maximum width, rounded distad and more or less conspicuosly curved-pointed proximad, exactly like the modern seeds, but averaging somewhat smaller. The specimens with the whole nut preserved are about 2.25 centimeters long, 1.7 centimeters in maximum width, and 1.3 centimeters in maximum thickness. These dimensions
are somewhat smaller than those of all average sized modern cashew nut, but these particular fossils may be somewhat below the average size of the fossils since several of the naked fossil seeds are larger than this. The largest of those in a collection of about two dozen is 2.4 centimeters in length, which would indicate that inthe fresh nut with its shell intact, and before shrinkage, the length was about 2.9 centimeters, which would be about the same size as the modern nuts.

Emended diagnosis

Manchester and Balmaki (2018: Spiny fruits revealed by nano-CT scanning: Pseudoanacardium peruvianum (Berry) gen. et comb. nov. from the early Oligocene Belén flora of Peru. – Acta Palaeobotanica 51(1): 44):
Chalcedony locule casts smooth-surfaced and cashew-shaped: reniform in overall form and rounded at one end and more pointed at other end, bisymmetrical, with keel in plane of symmetry, lensoidal to nearly circular in transverse outline. Locule casts 20–26 mm long, 8–15 mm wide (measured perpendicular to plane of symmetry), and 11–18 mm in dorsiventral depth. Fruit densely ornamented with spines except over raised area in ventral concavity. Excluding spines, fruits are 28–30 mm long, 11–14 mm wide (measured perpendicular to plane of symmetry), and 15.5–22 mm in dorsivental depth. Spines 1.6 mm long, 0.2 mm wide, stiff and terete. Endocarp wall surrounding locule casts, represented by empty space between locule cast surface and surface of sedimentary fruit mold, 1–1.3 mm thick, excluding spines. Large circular scar (8.0 mm in diameter (or ca 1/3 of full length of locule) centered on midpoint of ventral concavity of locule cast, and aligned with ventral protrusion. Remains of a wrinkled seed coat preserved within locule cast of some specimens indicate one seed per fruit.

Stratigraphy

Paleogene, Oligocene
early Oligocene

[stratigraphy according to Manchester and Balmaki (2018: Acta Palaeobot. 51(1): 41]

Locality

Peru
for lectotype (Manchester and Balmaki (2018: Acta Palaeobot. 51(1): 44):
The original specimens were collected by invertebrate paleontologist A.A. Olsson from a site indicated to be about 6 miles southeast of Parinas Point. We relocated the outcrops in 2010 (Manchester et al. 2012a) and obtained GPS readings of 4°44.946′S, 81°14.137′W (UF 602) and 4°44.966′S, 81°14.219′W (UF 603).

Berry (1924: p. 125): The specimens, which I owe to the courtesy of Dr. A. A. Olsson, the collector, are numerous, and come from the La Brea estate, about 6 miles southeast of Parinas Point in the Department of Piura, Peru.