一种早期的坎布里亚时代的类动物,具有类似放射虫的猛禽附属物
Han Zeng1,2,3, Fangchen Zhao4,5,6, Kecheng Niu7
1State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, China.
Nature
|November 5, 2020
概括
早期的欧类动物进化得到了Kylinxia zhangi的解释,这是一个连接Radiodonta和Deuteropoda的坎布里亚化石. 这一发现揭示了对附属物进化和早期关节动物关系的关键见解.
科学领域:
- 古生物学
- 进化生物学
- 遗传学
背景情况:
- 了解早期的类动物进化是类动物进化的一个重大挑战.
- 坎布里亚化石提供了关键的数据,但主要的类人群之间的相互关系仍在争论中.
- 放射性动物在遗传学上与欧类动物相近,在第二个头部部分 (Deuteropoda) 几乎是前部附属物,但存在差距.
研究的目的:
- 描述Kylinxia zhangi,一个来自早期坎布里亚时代成江生物群的新型甲足动物化石.
- 重建Kylinxia的遗传位置及其对早期欧类进化的影响.
- 调查早期足动物前肢的进化变化和同质性.
主要方法:
- 一种新的化石物种Kylinxia zhangi的描述,基于保存良好的标本.
- 包含Kylinxia和其他相关的坎布里亚和现存类型的基因组重建.
- 较量前肢和其它主要特征的形态分析.
主要成果:
- Kylinxia zhangi表现出Radiodonta和Deuteropoda的特征,包括多个眼睛和猛禽的额头附属物.
- 遗传学分析将Kylinxia作为Radiodonta和Deuteropoda之间的过渡分类.
- 这项研究支持放射性和巨前之间的同质性,并表明和天线的起源来自祖先的猛禽形式.
结论:
- Kylinxia提供了早期欧类动物的遗传关系的关键见解.
- 它揭示了前肢的演化变化和差异.
- 这些发现有助于了解足动物的关键进化创新的起源.
相关概念视频
02:56The Fossil Record
26.7K
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...
26.7K
01:27Diversity of Protists III
584
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,...
584
01:54Convergent Evolution
30.8K
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.
30.8K
01:23Surface Appendages of Archaea
421
Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, and motility. Among these appendages, pili and archaella stand out for their distinct morphologies and functionalities, enabling archaea to thrive in diverse and often extreme environments.Pili: Adhesion and Biofilm FormationPili are filamentous structures assembled from pilin protein subunits, primarily contributing to adhesion and biofilm...
421
01:09Overview of the Axial Skeleton
8.3K
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...
8.3K
01:51Lampbrush Chromosomes
8.4K
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
8.4K