Rannikko Janina, Adhikari Hari, Karme Aleksis, Žliobaitė Indre, Fortelius Mikael
Helsinki XR Center, Metropolia University of Applied Sciences, Helsinki, Finland.
Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland.
J Morphol. 2020 Mar;281(3):348-364. doi: 10.1002/jmor.21103. Epub 2020 Jan 30.
Two separate subfamilies of Plio-Pleistocene African pigs (suids) consecutively evolved hypsodont and horizodont molars with flat occlusal surfaces, commonly interpreted as an adaptive trait to a grazing diet, similar to that of the present warthogs (Phacochoerus spp.). To investigate this in detail, we studied the 3D-dental topography of fossil specimens from the Turkana Basin, using geographic information systems-based methods. To establish baselines for interpretation of the Turkana Basin suids, topography of third molars of extant suids with known diets were analyzed: grazing warthog (Phacochoerus africanus), herbivorous mixed-feeder forest hog (Hylochoerus meinertzhageni), omnivorous generalist wild boar (Sus scrofa), omnivorous fruit and tuber eater bush pig (Potamochoerus spp.), and omnivorous fruit eater babirusa (Babyrousa spp.) In addition, we analyzed supposedly browsing Miocene suids, Listriodon spp. The same topographic measures were applied to Plio-Pleistocene specimens from the Turkana Basin, Kenya: Notochoerus euilus, Notochoerus scotti, Kolpochoerus heseloni, and Metridiochoerus andrewsi. With some differences between techniques, 3D-dental topography analysis of extant suid molars mostly predicts the dietary differences between the species correctly. The grazing P. africanus differs from both the omnivorous suids and the herbivorous mixed-feeder H. meinertzhageni in all except one metrics. The omnivorous mostly tropical suids, Potamochoerus and Babyrousa, primarily differ from the generalist, S. scrofa, in the orientation patch count analysis, showing higher occlusal complexity in the latter. Although, there might be significant gaps between the morphological changes and the ecological changes, we conclude that based on comparison of dental topography with the present-day suids, N. scotti and M. andrewsi were most likely highly specialized grazers, while N. euilus and K. heseloni retained more of their ancestral, omnivorous heritage, but consumed grasses more than the extant omnivorous suids. RESEARCH HIGHLIGHTS: Dental topography can predict different diets in present-day wild pigs. The Plio-Pleistocene pigs in the Turkana Basin had dental topography mostly similar to extant grazing warthog, although some species also had resemblances to omnivorous forest pigs.
上新世 - 更新世的非洲猪（猪科动物）的两个不同亚科先后进化出了高冠齿和具有平坦咬合面的水平齿，通常被解释为适应放牧饮食的一种适应性特征，类似于现存的疣猪（非洲疣猪属）。为了详细研究这一现象，我们使用基于地理信息系统的方法，研究了来自图尔卡纳盆地的化石标本的三维牙齿地形。为了建立解释图尔卡纳盆地猪科动物的基线，我们分析了已知饮食的现存猪科动物第三磨牙的地形：放牧的疣猪（非洲疣猪）、食草的混合食性的大林猪（海氏大林猪）、杂食性的野猪（野猪）、杂食性的以水果和块茎为食的非洲灌丛野猪（非洲灌丛野猪属）以及杂食性的以水果为食的鹿豚（鹿豚属）。此外，我们还分析了推测为食叶的中新世猪科动物，利氏猪属。同样的地形测量方法也应用于来自肯尼亚图尔卡纳盆地的上新世 - 更新世标本：欧氏诺托猪、斯科特诺托猪、赫氏科尔波猪和安德鲁氏扁脸猪。尽管技术之间存在一些差异，但现存猪科动物磨牙的三维牙齿地形分析大多能正确预测物种之间的饮食差异。在所有指标中，除了一项外，放牧的非洲疣猪与杂食性猪科动物和食草的混合食性的海氏大林猪都有所不同。杂食性的主要生活在热带的非洲灌丛野猪和鹿豚，在方向斑块计数分析中，与杂食性的野猪主要的区别在于，后者显示出更高的咬合复杂性。尽管形态变化和生态变化之间可能存在显著差距，但我们得出结论，基于与现存猪科动物的牙齿地形比较，斯科特诺托猪和安德鲁氏扁脸猪很可能是高度特化的食草动物，而欧氏诺托猪和赫氏科尔波猪保留了更多其祖先的杂食性特征，但比现存的杂食性猪科动物消耗更多的草。研究亮点：牙齿地形可以预测现存野猪的不同饮食。图尔卡纳盆地的上新世 - 更新世猪的牙齿地形大多与现存的放牧疣猪相似，尽管有些物种也与杂食性的森林猪有相似之处。
