Carlos Castañeda-Posadas

Benemérita Universidad Autónoma de Puebla, México · Laboratorio de Paleontología

A variety of fruits and leaf compressions were collected from lacustrine sediments of the “Bloque Tlaxcala” (Miocene), San Esteban Tizatlán locality, Tlaxcala State, central Mexico. From this fossil material collected, we describe two new species belonging of Guarea (Meliaceae) and Petiveria (Phytolaccaceae), and one leaf form related to the genus...

The amber of Simojovel de Allende, Chiapas, Mexico, of Late Oligocene-Early Miocene age, has yielded a new flower representing the Meliaceae. The flower of Swietenia miocenica Castañeda-Posadas & Cevallos-Ferriz sp. nov. is characterized by small size; free calyx composed of five glabrous lobes, ciliolated along the margin lobes; corolla composed o...

The extant regional vegetation of Panotla, Tlaxcala, Mexico, is the result of its geography, mainly due to the buildup of the Mexican Trans-volcanic Belt. Before this volcanic belt originated, palaeobotanical evidence suggests that topographic, palaeoclimatic and ecological conditions were different, allowing the establishment of an evergreen tropi...

Six flowers preserved in Early Miocene amber from Simojovel, Chiapas were identified as members of the family Rhamnaceae. The flowers were designated as Gouania miocenica sp. nov. based on the following characteristics: small size, pentamerous, triangular sepals and cucullate petals, unguiculate at the base and rounded at the apex, enfolding the st...

Concern about the course of the current environmental problems has raised interest in investigating the different scenarios that have taken place in our planet throughout time. To that end, different methodologies have been employed in order to determine the different variables that compose the environment. In paleoecology, these variables are used...

In countries such as Mexico, fossil plants has been little used to reconstruct paleoenvironments and paleoclimates, although in other countries different methods have been developed to infer these environmental and climatic conditions in the past. The work on this subject has been carried out by associating fossil organisms (proxies) with their clo...

Libro de resúmenes del XI Congreso Latinoamericano de Paleontología en Quito , Ecuador en 2022

Neobuxbaumia tetetzo is a columnar cactus whose flowers are visited by the bat species Choeronycteris mexicana and Leptonycteris yerbabuenae. Although both bat species are considered the pollinators of N. tetetzo, the probability of pollination of each bat species has not been estimated. In this study, we determine the relative importance of C. mex...

Los estudios paleobotánicos realizados en el estado de Tlaxcala en los últimos veinte años han cambiado la visión sobre su importancia paleobiológica, que pasó de ser un sitio de recolecta de escasos fósiles del Pleistoceno a ser considerada una región rica en evidencias de la evolución de la flora mexicana en los últimos 15 millones de años (Ma)....

Background: Plant ecologists have developed methods to measure xylem drought resistance but these cannot be used in fossil woods. There is, however, one anatomical trait highly correlated with cavitation resistance: the squared vessel-wall thickness-to-span ratio ((t/b)2h). This metric though, could be in many cases impractical to measure in fossil...

Throughout the Holocene, two of the most important factors involved in the evolution of tropical coastlines have been fluctuations in sea level and regional climates. The geological record provides insightful realizations of the complex interaction between these two factors, improving our understanding of the evolution of littoral zones. Here we pr...

Pollination syndromes have been widely used to predict the groups of pollinators of plants. Their predictability has been demonstrated for plant species pollinated by bees, birds, and bats. However, the importance of other aspects on the predictability of pollination syndromes still remain unknown. For instance, plant life cycle has not been consid...

The study of the early Miocene amber of Simojovel de Allende, Chiapas, has taken a great interest, since it has been perceived that its study allows us to demonstrate an estuarine environment during its deposit. In this work, the identification of 34 specimens present in a piece of amber belonging to Museo del Ámbar Lilia Mijangos, with an approxim...

In this Paleontological Note, we explored the potential that vessel reinforcement metrics have to determine functional characteristics of fossil forests and how they can help to know their paleoecological characteristics. Essentially we tested how the vessel wall to lumen ratio compares to the vessel wall to span ratio, as the former is easier to m...

Fabaceae are one of the most diverse flowering-plant groups today, and in Mexico their presence is well represented since the late Cretaceous. In this work are reported two fossil woods from the El Bosque Formation, early Eocene of Southern Mexico. These new records show close resemblance with the modern wood of Kingiodendron (Detarioideae) and Ent...

Records of Pleistocene reptiles are relatively well known in different countries. However, reptile fossil records of Pleistocene from Latin America are scarce and limited to presence data associated with records of megafauna remains. Taphonomic studies in Pleistocene reptiles are focused on finding out the origin of the paleontological remains; tha...

The San José de Gracia Quarry, located within the Municipality of Molcaxac, southern Puebla, Mexico, is a new paleontological site discovered about a decade ago. This paper is the first formal scientific contribution of this site. The quarry occupies an area no larger than two hectares that are exploited for commercial purposes, where slabs are ext...

The fossils from San Mateo Huexoyucan, Tlaxcala, Mexico are formally described in this work. The specimens collected since 2011 include cranial and postcranial ele ments of Pleistocene Megafauna. The iden tification of the elements allows to postulate that they correspond to six previously reported species for the study area (Bison antiquus, Camelo...

Se describe una nueva especie del género-fósil Laurinoxylon procedente de la Formación El Bosque (Eoceno), Chiapas, México. La nueva especie presenta las siguientes características distintivas: porosidad difusa, vasos solitarios y en múltiples radiales, placas de perforación simple, pun- teaduras intervasculares alternas, punteaduras vaso-radio con...

En el presente trabajo se muestran resultados de la identificación de cinco fósiles vegetales incluidos en ámbar de Simojovel, Chiapas. Las estructuras estudiadas corresponden a dos flores pertenecientes a la Familia Arecaceae; a dos hojas compuestas (foliolos) pertenecientes a la Familia Fabaceae y una hoja aislada perteneciente a la Familia Myrta...

We describe a new fossil wood from the El Bosque Formation (Eocene) in Chiapas, southern Mexico. It has a combination of features found in the Anacardiaceae, including distinct growth rings, diffuse porosity, vessels solitary and in radial multiples of 2-3, simple perforation plates, medium to large alternate intervessel pits, vessel-ray parenchyma...

Se describen los fósiles de mamíferos pleistocénicos procedentes de la zona de San Mateo Huexoyucán, Tlaxca- la, México, alojados en la Colección Paleontológica de la Benemérita Uni- versidad Autónoma de Puebla. Se cuales seis son nuevos registros para el área de estudio (Bison antiquus, cf. Bison occidentalis, Camelops hesternus, Equus mexicanus,...

The purpose of this work is to provide a description of biomorphic structures found in sedimentary pyrite present in the organic-rich marine limestone of the Agua Nueva Formation (Upper Cenomanian, Upper Cretaceous), central Mexico, using scanning electron microscope images. Six types of biomorphic structures were found and interpreted as coccoids...

En este capítulo se describe el registro de las tres icnofaunas de dinosarios cretácicos de Puebla y se comenta sobre su importancia paleontológica y geológica.

En este capitulo se da una panorámica del desarrollo histórico de la paleomastozoología en Puebla, se presenta el registro de mamíferos del estado, incluyendo las localidades portadoras de huellas y se comenta sobre las perspectivas del registro poblano.

In this paper six fossil forms of Chrysophycean stomatocysts are described. The material was collected from sedimentary pyrite embedded in well-laminated organic-rich limestone of the Upper Cretaceous Agua Nueva Formation at the locality of Xilitla, Central Mexico. The stomatocysts are represented by two spherical speci-mens with smooth surfaces la...

The objective of this work is to provide a general description of pyritized pollen grains from Upper Cretaceous rocks from Mexico.

Specific gravity (SG) is a key functional trait that has been linked to plant life history traits (e.g. growth rate, life spans) and ecological properties (e.g. cavitation resistance, water transport capacity). SG estimation can thus provide important information about the ecological characteristics of fossil assemblages. Since SG is also related t...