Video Experimental Relacionado
Updated: Jan 5, 2026
08:02
Dissection and Flat-mounting of the Threespine Stickleback Branchial Skeleton
Published on: May 7, 2016
10.2K
Morfología del más antiguo tetrápodo reconstruible Parmastega aelidae
Pavel A Beznosov1, Jennifer A Clack2, Ervīns Lukševičs3
1Institute of Geology, Komi Science Centre, Ural Branch of the Russian Academy of Sciences, Syktyvkar, Russia.
Nature
|October 25, 2019
Resumen
Parmastega aelidae, un tetrápodo devónico temprano de Rusia, ofrece nuevas ideas sobre la evolución de los vertebrados. Este fósil proporciona datos cruciales sobre la anatomía temprana de los tetrápodos y las relaciones evolutivas.
Área de la Ciencia:
- Paleontología
- Biología evolutiva
- Paleontología de los vertebrados
Sus antecedentes:
- La diversidad de tetrápodos del Devónico ha crecido, pero los fósiles son a menudo fragmentarios.
- Los fósiles clave como Ichthyostega y Acanthostega dominan nuestra comprensión de los primeros tetrápodos.
- Los fósiles existentes son más jóvenes que las primeras huellas y fragmentos de tetrápodos.
Objetivo del estudio:
- Para describir un nuevo tetrápodo Famenniano temprano, Parmastega aelidae.
- Para reconstruir el cráneo y el cinturón del hombro de P. aelidae utilizando material 3D.
- Para inferir la posición paleobiológica y filogenética de P. aelidae.
Principales métodos:
- Descripción del material fósil de Rusia.
- Reconstrucción del cráneo y el cinturón del hombro.
- Análisis filogenéticos basados en Bayes y parsimonia.
Principales resultados:
- Parmastega aelidae gen. y sp. Nov. se describe desde el Famenniano más antiguo (aprox. Hace 372 millones de años).
- El material 3D permitió la reconstrucción del cráneo y el cinturón del hombro.
- P. aelidae exhibe características que sugieren un estilo de vida acuático y de crucero por la superficie.
- Los análisis filogenéticos colocan a Parmastega como hermana de todos los demás tetrápodos en la mayoría de los árboles.
Conclusiones:
- Parmastega aelidae representa uno de los tetrápodos más antiguos y basales conocidos.
- Este descubrimiento mejora nuestra comprensión de la evolución y diversificación de los primeros tetrápodos.
- Los hallazgos proporcionan un punto de datos crucial para la transición de la vida acuática a la terrestre.
Videos de Conceptos Relacionados
02:56The Fossil Record
27.0K
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
27.0K
01:56Gastrulation
65.5K
Gastrulation establishes the three primary tissues of an embryo: the ectoderm, mesoderm, and endoderm. This developmental process relies on a series of intricate cellular movements, which in humans transforms a flat, “bilaminar disc” composed of two cell sheets into a three-tiered structure. In the resulting embryo, the endoderm serves as the bottom layer, and stacked directly above it is the intermediate mesoderm, and then the uppermost ectoderm. Respectively, these tissue strata...
65.5K
01:27Diversity of Protists III
691
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
691
01:23Phylogeny
56.5K
Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon (singular). Taxa (plural) can span different levels of the evolutionary hierarchy. For instance, the group containing all birds is a taxon (comprising the class Aves), and the group of all species of daisies (the genus Bellis) is a taxon. Phylogenies can likewise include just one genus (i.e., depict species relationships) or span an entire kingdom.
56.5K
01:15Diversity of Protists I
794
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
794
01:09Overview of the Axial Skeleton
8.8K
The skeleton is subdivided into two major divisions—the axial skeleton and the appendicular skeleton. The axial skeleton forms the vertical, central axis of the body. It includes all of the bones of the head, neck, chest, and back. It protects the brain, spinal cord, heart, and lungs. It also serves as the attachment site for muscles that move the head, neck, and back and for muscles that act across the shoulder and hip joints to move their corresponding limbs.
The axial skeleton of the...
The axial skeleton of the...
8.8K