Zamuneria amyla L.C.A.Martínez, A.Iglesias et Artabe in Martínez, Iglesias, Artabe, Varela & Apesteguía

Plant Fossil Names Registry Number: PFN002384

Act LSID: urn:lsid:plantfossilnames.org:act:2384

Authors: L. C. A. Martínez, A. Iglesias & A. E. E. Artabe

Rank: species

Genus: Zamuneria L.C.A.Martínez, A.Iglesias et Artabe in Martínez, Iglesias, Artabe, Varela & Apesteguía

Reference: Martínez, L. C. A., Iglesias, A., Artabe, A. E. E., Varela, A. N. & Apesteguía, S. (2017): A new Encephalarteae trunk (Cycadales) from the Cretaceous of Patagonia (Mata Amarilla Formation, Austral Basin), Argentina. – Cretaceous Research 72: 81–94., link

Page of description: 84

Illustrations or figures: figs 3–11

Name is type for

Zamuneria L.C.A.Martínez, A.Iglesias et Artabe in Martínez, Iglesias, Artabe, Varela & Apesteguía 2017

Types

Holotype MPM-Pb-17527, Museo Padre Molina, Santa Cruz Province, Argentina
Figures: fig. 3

Note: Specimens LPPB-14021, pmLPPB-1938 to pmLPPB-1949 (housed in the Collection of the Paleobotany Division of Museo de La Plata (LPPB), La Plata, Argentina) are called isotypes by Martínez et al. (2017: Cretac. Res., 72: 83) but they are, in fact, parts of holotype.

fig. 4: pmLPPB-1938
fig. 5: pmLPPB-1938–pmLPPB-1940
fig. 6: pmLPPB-1941–pmLPPB-1943
fig. 7: pmLPPB-1939–pmLPPB-1944
fig. 9: pmLPPB-1945–pmLPPB-1946
fig. 11: pmLPPB-1943

Original diagnosis/description

A columnar and polyxylic stem, covered by persistent rhomboidal leaf bases and cataphylls. A wide and parenchymatous central pith with mucilage canals, idioblasts and medullary vascular bundles. The vascular system comprises a medullary vascular system, and a cylindrical vascular system. The medullary vascular system is composed of many scattered medullary vascular bundles. The cylindrical vascular system has concentric rings of centrifugal secondary xylem and phloem (polyxylic) toward the cortex, separated by wide multiseriate parenchymatic rays (primary rays). Primary rays with vascular bundles and mucilage canals. Tracheids of secondary xylem with uni- to triseriate contiguous and alternate bordered pits in walls. Manoxylic secondary xylem and phloem with homocellular multiseriate rays, with one to three cells wide (secondary rays). Cortex composed of fundamental parenchyma cells and idioblasts, mucilage canals and girdling leaf traces.

Etymology

The name of species is derived from Latin noun amylum (starch), by the abundance of parenchyma cells with lots of starch grains in the fossil stem.

Stratigraphy

Cretaceous, Upper Cretaceous, Cenomanian
Mata Amarilla Formation, lower Upper Cretaceous (middle Cenomanian)

Today it is referred to Campanian?-Maastrichtian Cerro Fortaleza Formation (see Sickmann et al. 2018: Basin Research, 30(4): 708–729; Moyano Paz et al. 2019: Latin American Journal of Sedimentology and Basin Analysis, 25(2): 69–92).

Locality

Argentina
Cerro Fortaleza locality (49° 56 40 S, 72° 03 50 W), Santa Cruz Province

Plant fossil remain

fossil wood