The evolutionary history of Bison is a matter of debate due to the scarcity of fossil remains from the earliest members of this clade and the close morphological similarities among species. To clarify the taxonomic status of the earliest stouter bison and their relationships to their putative ancestor, Leptobos, as well as other primitive forms traditionally referred to subgenus Bison (Eobison), we carry out a complete revision of the available European fossil record, with a focus on the forms occurring during the Early-Middle Pleistocene Transition. Emphasis is put on the description of the unpublished Bison remains from the Vallparadís Composite Section (VCS), including the sites of Cal Guardiola and Vallparadís Estació (Terrassa, NE Iberian Peninsula). VCS fossiliferous layers yielded one of the richest faunal assemblages from the European latest Early Pleistocene and one of the few European fossil sites covering almost entirely the Early-Middle Pleistocene Transition (1.2–0.6 Ma). The collection comprises thousands of ungulates remains, especially abundant fossils of a large Bison species. The morphology of the postcranial sample from VCS fits that of Bison (Bison) schoetensacki, i.e., the earliest stout bison (Bison s.s.) recorded in Europe. We studied more than 200 cranial and postcranial elements with a focus on the metapodial remains. Comparisons were performed with all the available fossil record of Pleistocene Eurasian fossil Bison species. We confirm the taxonomic validity of B. schoetensacki and recognize distinct eco-morphotypes of European bison between the late Early Pleistocene and the beginning of the Holocene based on the size and proportions of the metapodials. Although the appendicular skeleton shows reliable characters for the diagnosis of different species, the great morphological homogeneity recognized within the genus requires a cautious approach in systematic studies based on postcranial material.

野牛的进化史是一个有争议的问题，因为该进化枝最早的成员化石遗体稀少，并且物种之间的形态相似性极高。为了弄清最早的野性野牛的分类学地位及其与假定的祖先Leptobos的关系，以及其他传统上被称为Bison属（Eobison）的原始形式，我们对现有的欧洲化石记录进行了完整的修订，其中包括重点关注早中中期更新世期间发生的形式。重点放在未发布的野牛的描述上遗骸来自瓦尔帕拉迪斯综合区（VCS），包括卡尔瓜迪奥拉和瓦尔帕拉迪斯Estació（东北伊比利亚半岛特拉萨）的遗址。VCS的化石层是欧洲最新的更新世产生的最丰富的动物群组合之一，也是几乎覆盖了整个早期-中期更新世（1.2-0.6 Ma）的少数欧洲化石遗址之一。该集合包括成千上万的有蹄类动物遗骸，特别是大型野牛物种的丰富化石。来自VCS的颅后样本的形态符合Bison（Bison）schoetensacki的形态，即最早的粗壮的野牛（Bison）。ss）录制在欧洲。我们研究了200多个颅骨和颅后元件，重点是掌足残骸。与更新世欧亚大陆化石野牛物种的所有可用化石记录进行了比较。我们确认B的分类学有效性。schoetensacki并根据后生动物的大小和比例，识别出早更新世晚期和全新世开始之间欧洲野牛的独特生态型。尽管阑尾骨骼显示出可用于诊断不同物种的可靠特征，但是在基于颅后材料的系统研究中，该属中公认的巨大形态同质性需要谨慎的方法。