Cuticular study of Bennettitales from the Springhill Formation, Lower Cretaceous of Patagonia, Argentina

Cuticles of leaves and scale-leaves belonging to the order Bennettitales are discussed using light microscopy (LM) and scanning and transmission electron microscopy (SEM and TEM). The cuticles occur in the Springhill Formation (Lower Cretaceous) of Santa Cruz Province, Argentina. The fossil group is...

Descripción completa

Detalles Bibliográficos
Autor: Villar, Liliana Monica
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2001
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/136898
Acceso en línea:http://hdl.handle.net/11336/136898
Access Level:acceso abierto
Palabra clave:ARGENTINA
BENNETTITALES
CUTICLES
LOWER CRETACEOUS
SANTA CRUZ PROVINCE
SPRINGHILL FORMATION
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descripción
Sumario:Cuticles of leaves and scale-leaves belonging to the order Bennettitales are discussed using light microscopy (LM) and scanning and transmission electron microscopy (SEM and TEM). The cuticles occur in the Springhill Formation (Lower Cretaceous) of Santa Cruz Province, Argentina. The fossil group is represented by seven species of which one is new and three other species have their diagnosis emended by ultrastructural analysis. The species studied are Otozamites patagonicus sp. nov., Otozamites archangelskyi Baldoni and Taylor, 1983, Pterophyllum trichomatosum Archangelsky and Baldoni, 1972, Ptilophyllum valvatum Villar de Seoane, 1995, Ptilophyllum antarcticum (Halle) Archangelsky and Baldoni, 1972, Cycadolepis coriacea Menéndez, 1966 and Cycadolepis involuta Menéndez, 1966. The leaves and scale-leaves show xeromorphic characters such as sculptured surfaces, sunken stomata and a thick external wall in the epidermis. The xeromorphic characters could indicate high temperatures, low humidity and arid soils. These palaeoenvironmental conditions may have been associated with volcanic activity. The presence of carbonized specimens also suggests the development of forest fires produced by dry seasonal conditions or regional volcanic activity.