初期のペルム紀の2足の爬虫類である爬虫類.
D S Berman1, R R Reisz, D Scott
1Section of Vertebrate Paleontology, Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA 15213, USA.
Science (New York, N.Y.)
|November 4, 2000
まとめ
ドイツの2億9千万年前の化石爬虫類Eudibamus cursorisは,初期のカーソリアル双足の動きを示しています. この発見は,ラウラシアで知られている最も古いパラレプチリアとボロサウリドの分布を明らかにしています.
科学分野:
- パレオントロジー・パレオントロジー
- 脊椎動物の古生物学について
- 進化生物学の進化生物学について
背景:
- 爬虫類の初期の進化とその移動は,胎児の多様化を理解するために重要である.
- ボロサウリidaeは,分布と生態学的役割が十分に理解されていない初期の爬虫類のグループを表しています.
研究 の 目的:
- ドイツの低ペルミアンから新しい化石爬虫類,Eudibamus cursorisを記述するために.
- E. cursoris.の運動能力と系統的位置を調査する.
- ParareptiliaとBolosauridaeの初期の進化と分布についての洞察を提供するために.
主な方法:
- よく保存された爬虫類の骨格の詳細な形態学的分析.
- 他の初期の爬虫類との比較解剖学的研究.
- アムニオタ.内のE.カーソリスの位置を決定するための系統遺伝分析.
主要な成果:
- 2億9千万年前の骨格は,Eudibamus cursoris, gen. et sp. を表しています. Nov. 小さなボロサウリド.
- E. cursorisは,パラサギタル・ディジテグラード姿勢を含む,カーソリアル・バイペダル・ロコモーションの適応を示しています.
- この発見は,初期ペルム期にラウラシアにボロサウリデスが存在していたことを確認するものである.
- E. cursorisは,Parareptilia.の最も古い既知のメンバーとして特定されています.
結論:
- エウディバムス・カーソリスは,爬虫類におけるカーソリアル・バイペダリズムの最古の証拠を提供している.
- この発見により,ペルミア初期におけるボロサウリidaeの既知の地理的範囲が拡大した.
- E. cursorisは,知られている最も古いパラレプチリアを代表し,この主要な爬虫類クラドの多様化に光を当てています.
関連する概念動画
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...
01:06Fixed Action Patterns
A fixed action pattern (FAP) is a specific, hard-wired sequence of behaviors that occurs in response to an external stimulus, called a sign stimulus. The behavior is “fixed” because it is essentially unchangeable—proceeding similarly across individuals of a species every time it occurs.
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...
01:54Convergent Evolution
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...