摘要翻译：
棘皮动物的五趾组织被认为是在类似翼枝的祖先的躯干膨胀期间肠道内部U形肠系膜重组的结果。在这种情况下，肠系膜环在五个液压凸起之间通过三种不同的机制发展：（1）早期形成两个额外的环，直接导致五个液压凸起；（2）随后形成两个额外的环，导致最初三个和后来五个液压凸起；或（3）身体膨胀而不形成环。因此，棘皮动物至少有三种主要的进化途径。棘皮动物的解剖结构，如步行系统或骨囊，在两个谱系中独立发展。从所有这三条路径中，可以导出与化石和现存棘皮动物相匹配的各种身体结构。刺突动物和最早的五足棘皮动物很可能是从直接五足途径进化而来的，而三足棘皮动物和那些在三足对称上叠加了五足组织的棘皮动物很可能是沿着间接途径进化而来的。不对称或双侧对称棘皮动物是从第三支付道进化而来的。讨论和描述了导致直接和间接五趾棘皮动物的最重要的形态变化。
---
英文标题：
《Hydromechanical considerations on the evolution and diversification of
  the echinoderm bauplans》
---
作者：
Michael Gudo
---
最新提交年份：
2005
---
分类信息：

一级分类：Quantitative Biology        数量生物学
二级分类：Populations and Evolution        种群与进化
分类描述：Population dynamics, spatio-temporal and epidemiological models, dynamic speciation, co-evolution, biodiversity, foodwebs, aging; molecular evolution and phylogeny; directed evolution; origin of life
种群动力学；时空和流行病学模型；动态物种形成；协同进化；生物多样性；食物网；老龄化；分子进化和系统发育；定向进化；生命起源
--
一级分类：Quantitative Biology        数量生物学
二级分类：Other Quantitative Biology        其他定量生物学
分类描述：Work in quantitative biology that does not fit into the other q-bio classifications
不适合其他q-bio分类的定量生物学工作
--

---
英文摘要：
  The pentaradial organisation of echinoderms is postulated to have evolved as the result of the reorganisation of the internal U-shaped mesentery of the intestinal tract during inflation of the trunk of a pterobranch-like ancestor. Under this scenario, loops of the mesentery developed between five hydraulic bulges by three different mechanisms: (1) by the early formation of two additional loops resulting directly in five hydraulic bulges, (2) by the subsequent formation of two additional loops resulting in the formation of initially three and then five hydraulic bulges or (3) by the inflation of the body without formation of loops. Accordingly there are at least three main evolutionary pathways within the echinoderms. The anatomical structures, such as the ambulacral system or the skeletal capsule, which characterize the echinoderms, developed independently in both lineages. From all the three pathways various body structures can be derived matching those found in fossil and extant echinoderms. The eleutherozoans and the earliest pentaradial echinoderms most likely evolved from the direct-pentaradial pathway whereas triradiate echinoderms and those which show a pentaradial organisation superimposed on triradial symmetry, likely evolved along the indirect pathway. The asymmetric or bilateral symmetric echinoderms evolved from the third paythway. The most important morphological transformations leading to the directly and indirectly pentaradial echinoderms are discussed and described.
---
PDF链接：
https://arxiv.org/pdf/q-bio/0505036