A partial skeleton of the putative stem group roller Septencoracias is described from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). With an age of about 55 million years, the bones represent one of the earliest fossil records of a coraciiform bird. The new fossil reveals that the proximal pedal phalanges of the three anterior toes of Septencoracias exhibit markedly widened distal ends. This distinctive trait is not found in other representatives of the Coracii, but occurs in the Meropidae (bee-eaters). The quadrate likewise exhibit a derived characteristic of the Meropidae, and the beak is narrower than in rollers. These previously unnoticed features are of particular interest, because the Meropidae result as the sister taxon of the Coracii in sequence-based analyses. Calibrated molecular data suggest that the divergence between the Coracii and the Meropidae occurred at 55.6 Ma, with the new fossil being only slightly younger than this date. However, phylogenetic analyses recovered Septencoracias within the Coracii, so that the derived features shared with the Meropidae most likely are either plesiomorphic and were lost in the Coracii, or they represent parallelisms that evolved convergently in Septencoracias and the Meropidae. In any case, these traits suggest that Septencoracias differed from extant rollers in its ecological preferences and foraging mode.

来自 Walton-on-the-Naze（英国埃塞克斯郡）的始新世早期伦敦粘土描述了推定的茎组滚轴Septencoracias的部分骨架。这些骨头大约有 5500 万年的历史，是最早的喙形鸟类化石记录之一。新化石揭示了Septencoracias三个前脚趾的近端足趾显示出明显加宽的远端。这种独特的特征在Coracii的其他代表中没有发现，但在Meropidae（食蜂鸟）中发现。方形同样表现出鸟尾纲的衍生特征，并且喙比辊窄。这些以前未被注意到的特征特别令人感兴趣，因为在基于序列的分析中，猴头科是 Coracii 的姐妹分类群。校准的分子数据表明 Coracii 和 Meropidae 之间的分歧发生在 55.6 Ma，新化石只比这个日期稍年轻。然而，系统发育分析恢复了Septencoracias在 Coracii 中，因此与 Meropidae 共享的派生特征最有可能是拟形的并且在 Coracii 中丢失了，或者它们代表了在Septencoracias和 Meropidae 中趋同进化的平行性。在任何情况下，这些特征表明Septencoracias在生态偏好和觅食方式上与现存的滚轮不同。