Abstract

The evolutionary transition of a living organization to a new stable state begins with the disturbance of its previous equilibrium and, thus, with an increase in organizational disorderliness. The study of the traces of such disturbances was conducted based on the change of terrestrial vertebrate communities during the transition to the Mesozoic. It has been shown that the most common among such traces are the following: (a) “precocious” emergence of future dominants; (b) “Lazarus”-effect, i.e. return to the fossil record of previously disappeared forms; (c) the emergence of “disaster taxa”; and (d) the effect of “archaic diversity”. An analysis of the early phase of this transition (Middle Permian crisis), recorded in the Sundyr tetrapod fauna of Eastern Europe, shows that any kind of disturbance in the organization of a community may be equally a symptom of other typical violations as well. In particular, the precocious appearance of amphibian groups characteristic of the Late Permian—dvinosaurids and chroniosuchids—implies, along with this, the “Lazarus”-effect in the first case and the emergence of a “disaster taxon”, along with the effect of archaic diversity—in the second. The possibility of revealing similar symptoms of equilibrium disturbance in some other Middle Permian faunas is considered.

中文翻译：

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古代四足动物群落变迁过程中的组织平衡扰动：其在二叠纪中后期的表现

摘要

一个有生命的组织向新的稳定状态的进化转变始于其先前平衡的扰动，因此，随着组织无序性的增加。对此类扰动痕迹的研究是根据陆生脊椎动物群落向中生代过渡的变化进行的。已经表明，这些痕迹中最常见的有以下几种： (a) 未来支配者的“早熟”出现；(b) “拉撒路”效应，即回到以前消失形式的化石记录；(c) “灾害分类群”的出现；(d) “古老的多样性”的影响。对这种转变的早期阶段（中二叠纪危机）的分析，记录在东欧的 Sundyr 四足动物群中，表明社区组织中的任何类型的干扰也可能同样是其他典型违规行为的症状。特别是，二叠纪晚期两栖类群——龙龙科和计时鳄科——的早熟出现意味着，与此一起，第一种情况下的“拉撒路”效应和“灾难分类群”的出现，以及古老的多样性——在第二个。考虑了在其他一些中二叠纪动物群中揭示类似平衡紊乱症状的可能性。以及古代多样性的影响——在第二种情况下。考虑了在其他一些中二叠纪动物群中揭示类似平衡紊乱症状的可能性。以及古代多样性的影响——在第二种情况下。考虑了在其他一些中二叠纪动物群中揭示类似平衡紊乱症状的可能性。