Brochuchus is a small crocodylid originally based on specimens from the early Miocene of Rusinga Island, Lake Victoria, Kenya. Here, we report occurrences of Brochuchus from several early and middle Miocene sites. Some are from the Lake Victoria region, and others are in the Lake Turkana Basin. Specimens from the middle Miocene Maboko locality form the basis of a new species, Brochuchus parvidens, which has comparatively smaller maxillary alveoli. Because of the smaller alveoli, the teeth appear to be more widely spaced in the new species. We also provide a revised diagnosis for Brochuchus and its type species, B. pigotti. A phylogenetic analysis supports a close relationship between Brochuchus and tube-snouted Euthecodon, but although relationships among crocodylids appear poorly resolved in the set of optimal trees, this is because Brochuchus and Euthecodon, along with early Miocene “Crocodylus” gariepensis from the early Miocene of Namibia, jointly adopt two distinct positions—either closely related to the living sharp-nosed crocodile (Mecistops) or to a group including the living dwarf crocodiles (Osteolaemus). Character support for a close relationship with Mecistops is problematic, and we suspect a closer relationship to Osteolaemus will be recovered with improved sampling, but the results here are ambiguous. In either case, Brochuchus is more closely related to living groups not currently found in East Africa. This material helps constrain the timing of crocodylian faunal turnover in the East African Rift Valley System, with endemic lineages largely being replaced by Crocodylus in the middle or late Miocene possibly in response to regional xerification and the replacement of continuous rainforest cover with open grasslands and savannas.UUID: http://zoobank.org/e6f0b219-5f3e-44e5-bdb9-60a4fae8d126

中文翻译：

---

肯尼亚中新世中新世的一种新鳄鱼及非洲晚新生代鳄鱼动物群变化的时间

布罗库斯是一种小型鳄鱼，最初取材于肯尼亚维多利亚湖鲁辛加岛中新世早期的标本。在这里，我们报告发生布罗库斯来自几个中新世早期和中期的遗址。有些来自维多利亚湖地区，有些来自图尔卡纳湖盆地。来自中新世 Maboko 地区的标本构成了新物种的基础，小凤仙花，其上颌肺泡相对较小。由于肺泡较小，新物种的牙齿间距似乎更大。我们还提供修订的诊断布罗库斯及其模式种，乙.皮戈蒂. 系统发育分析支持两者之间的密切关系布罗库斯和管状的Euthecodon，但尽管鳄鱼科动物之间的关系在最优树的集合中似乎很难解决，这是因为布罗库斯和Euthecodon，以及早中新世“鳄鱼”加里普西斯来自纳米比亚早中新世，共同采取两种不同的立场——与现存的尖鼻鳄鱼密切相关（米西斯托) 或包括活的侏儒鳄鱼在内的一群人 (骨鱼）。性格支持与亲密关系米西斯托是有问题的，我们怀疑与骨鱼将通过改进的采样恢复，但这里的结果是模棱两可的。在任一情况下，布罗库斯与目前在东非没有发现的生物群更密切相关。这种材料有助于限制东非裂谷系统中鳄鱼动物群更替的时间，地方性谱系在很大程度上被取代鳄鱼在中新世中期或晚期，可能是为了响应区域干旱和用开阔的草原和稀树草原取代连续的雨林覆盖。UUID：http://zoobank.org/e6f0b219-5f3e-44e5-bdb9-60a4fae8d126