Data from: The relationships of the Euparkeriidae and the rise of Archosauria

For the first time, a phylogenetic analysis including all putative euparkeriid taxa is conducted, using a large data matrix analysed with maximum parsimony and Bayesian analysis. Using parsimony, the putative euparkeriid Dorosuchus neoetus from Russia is the sister taxon to Archosauria+Phytosauria. Euparkeria capensis is placed one node further from the crown, and forms a euparkeriid clade with the Chinese taxa Halazhaisuchus qiaoensis and ‘Turfanosuchus shageduensis’, and the Polish taxon Osmolskina czatkowicensis. Using Bayesian methods, Osmolskina and Halazhaisuchus are sister taxa within Euparkeriidae, in turn sister to ‘Turfanosuchus shageduensis’ and then Euparkeria capensis. Dorosuchus is placed in a polytomy with Euparkeriidae and Archosauria+Phytosauria. Although conclusions remain tentative due to low node support and incompleteness, a broad phylogenetic position close to the base of Archosauria is confirmed for all putative euparkeriids, and the ancestor of Archosauria+Phytosauria is optimized as similar to euparkeriids in its morphology. Ecomorphological characters and traits are optimized onto the maximum parsimony strict consensus phylogeny presented using squared change parsimony. This optimization indicates that the ancestral archosaur was probably similar in many respects to euparkeriids, being relatively small, terrestrial, carnivorous and showing relatively cursorial limb morphology; this Bauplan may have underlain the exceptional radiaton and success of crown Archosauria.本研究首次针对所有疑似派克鳄科（Euparkeriidae）类群开展系统发育分析，采用大型数据矩阵，分别通过最大简约法（maximum parsimony）与贝叶斯分析（Bayesian analysis）进行推演。基于最大简约法分析结果，产自俄罗斯的疑似派克鳄类德罗苏鳄（Dorosuchus neoetus）为主龙类（Archosauria）+植龙目（Phytosauria）的姊妹群；开普敦派克鳄（Euparkeria capensis）则距离冠群节点更远一步，且与中国类群桥街哈拉兹鳄（Halazhaisuchus qiaoensis）、‘沙疙瘩吐鲁番鳄’（‘Turfanosuchus shageduensis’）以及波兰类群查特科文奥斯莫尔斯卡鳄（Osmolskina czatkowicensis）共同构成派克鳄科演化支。采用贝叶斯方法推演时，奥斯莫尔斯卡鳄与哈拉兹鳄构成派克鳄科内的姊妹群，二者依次为‘沙疙瘩吐鲁番鳄’的姊妹群，随后与开普敦派克鳄形成姊妹关系；德罗苏鳄则被置于派克鳄科与主龙类+植龙目之间的多歧支（polytomy）中。尽管受限于较低的节点支持度（node support）与类群完整性，研究结论仍具一定试探性，但所有疑似派克鳄类群的系统发育位置均被证实紧邻主龙类基部；同时主龙类+植龙目的共同祖先在形态特征上被优化为与派克鳄类相似。本研究采用平方变化简约法（squared change parsimony），将生态形态特征映射至本次研究得到的最大简约法严格合意系统发育树（strict consensus phylogeny）之上。该特征映射结果显示，冠群主龙类的祖先类群在诸多方面与派克鳄类高度相似：体型相对小巧、营陆生生活、为肉食性动物，且具有较为特化的奔跑型肢体形态；这一躯体构型（Bauplan）或许为冠群主龙类的卓越辐射演化与演化成功奠定了演化基础。