Video Experimental Relacionado
Updated: Jul 18, 2026
09:31
Expression of Fluorescent Proteins in Branchiostoma lanceolatum by mRNA Injection into Unfertilized Oocytes
Published on: January 12, 2015
Los reptiles marinos del Triásico dieron a luz a crías vivas
Yen-Nien Cheng1, Xiao-Chun Wu, Qiang Ji
1National Museum of Natural Science, 1 Kuan Chien Road, Taichung 404, Taiwan, China.
Nature
|November 19, 2004
Resumen
La evidencia fósil revela que los antiguos reptiles marinos llamados sauropterigios dieron a luz a crías vivas (viviparidad), no ponen huevos. Este descubrimiento arroja luz sobre las estrategias reproductivas de estos diversos reptiles del Mesozoico.
Área de la Ciencia:
- Paleontología Paleontología.
- Biología Marina Biología Marina.
- Biología evolutiva Biología evolutiva.
Sus antecedentes:
- Los sauropterigios fueron un grupo dominante de reptiles marinos a lo largo de la Era Mesozoica.
- Sus estrategias reproductivas, específicamente la oviparidad frente a la viviparidad, permanecieron desconocidas a pesar de los numerosos descubrimientos de fósiles.
- Las hipótesis anteriores sugirieron viviparidad para algunos grupos sauroptéricos, pero carecían de evidencia directa.
Videos de Conceptos Relacionados
01:33Cleavage and Blastulation
After a large-single-celled zygote is produced via fertilization, the process of cleavage occurs while zygotes travel through the uterine tube. Cleavage is a mitotic cell division that does not result in growth. With each round of successive cell division, daughter cells get increasingly smaller.
01:56Gastrulation
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 will form...
00:55Parental Care
Many animals exhibit parental care behavior, including feeding, grooming, and protecting young offspring. Parental care is universal in mammals and birds, which often have young that are born relatively helpless. Several species of insects and fish, as well as some amphibians, also care for their young.
02:22The Colonization of Land
Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...
02:35What is Evolutionary History?
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.Phylogenetic trees illustrate the evolutionary relationships among these organisms. Scientists infer organisms’ common ancestry by evaluating shared morphological and genetic characteristics. Together, the fossil...
02:56The Fossil Record
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...