Abstract Detail

Paleobotany

Centeno, Naylet [1], Estrada-Ruiz, Emilio [2], Porras-Múzquiz, Héctor [3].

Late Cretaceous angiosperm leaves from Olmos Formation (upper Campanian), Coahuila, Mexico.

The Olmos Formation (upper Campanian) in Sabinas Basin is located in Northern Mexico. The formation represents a deltaic system along a coastal plain and is important for its extensive coal resources and the abundance of fossil plants. Despite that the fossils collected in the Olmos flora comprises over 100 morphotypes, there have been identified no more of 20% of material. Published descriptions of angiosperm leaves include members of Palmae, Rhamnaceae, Lauraceae, and Nelumbonaceae. In this work, we describe three new morphotypes of angiosperm leaves. The morphotype 1 shows an elliptic-ovate lamina, mesophyll size, rounded apex, convex base, dentate margin, primary vein pinnate, secondary veins semicaspedodromous, with a constant distribution through the lamina, one inter-secondary vein per inter-costal region, tertiary veins percurrent opposite straight, and quaternary veins polygonal reticulate. This morphotype resembles Boraginaceae and Elaeocarpaceae. The morphotype 2 has an ovate laminar form, notophyll size, straight apex, rounded base, entire-crenate margin, primary venation pinnate, secondary veins simple brochidodromous, two basal secondary veins, tertiary veins percurrent opposite straight, with a perpendicular-obtuse angle respect to mid-vein, quaternary venation reticulate, fifth order veins reticulate, fimbrial marginal vein present. These characters are present in Caprifoliaceae. Lastly, the morphotype 3, has an elliptic-rounded form, microphyll size, rounded apex, concave-convex base, crenate margin, primary veins palmately basal actinodromous, secondary veins semicrapedrodomous, with irregular space between intercostal secondary veins trough the margin, tertiary venation convex and chevron, with perpendicular angle respect to mid-vein, fimbrial marginal vein. These new records support the notion of the presence of a very diverse flora with paratropical elements in northern of Mexico. The fossil record of the formation provides key data to help us understanding the origin of the tropical flora that today exists in the country.

1 - Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s/n, Santo Tomás, Ciudad de México, MX, 11340
2 - Instituto Politécnico Nacional, Departamento de Zoología, Prolongación de Carpio y Plan de Ayala s/n,, Col. Santo Tomás, Ciudad de México, MX, 11340
3 - Museo de Múzquiz, Zaragoza 209, Melchor Múzquiz, 26340

Keywords:
Cretaceous
Angiosperm
Olmos Formation.

Presentation Type: Poster
Session: P, Paleobotany posters
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PPB002
Abstract ID:116
Candidate for Awards:None