Kargopoulos Nikolaos, Marugán-Lobón Jesús, Chinsamy Anusuya, Agwanda Bernard R, Brown Michael Butler, Fennessy Stephanie, Ferguson Sara, Hoffman Rigardt, Lala Fredrick, Muneza Arthur, Mwebi Ogeto, Otiende Moses, Petzold Alice, Winter Sven, Zabeirou Abdoul Razack Moussa, Fennessy Julian
Department of Biological Science, University of Cape Town, Cape Town, South Africa.
Giraffe Conservation Foundation, Windhoek, Namibia.
PLoS One. 2024 Dec 19;19(12):e0315043. doi: 10.1371/journal.pone.0315043. eCollection 2024.
Giraffe (Giraffa spp.) are among the most unique extant mammals in terms of anatomy, phylogeny, and ecology. However, aspects of their evolution, ontogeny, and taxonomy are unresolved, retaining lingering questions that are pivotal for their conservation. We assembled the largest known dataset of Giraffa skulls (n = 515) to investigate patterns of cranial variability using 3D geometric morphometrics. The results show distinct sexual dimorphism and divergent ontogenetic trajectories of skull shape for the north clade (G. camelopardalis antiquorum, G. c. camelopardalis, G. c. peralta, and G. reticulata) and the south clade (G. giraffa angolensis, G. g. giraffa, G. tippelskirchi tippelskirchi, and G. t. thornicrofti) which was further supported statistically. Discriminant functions found statistically significant cranial shape differences between all four Giraffa species, and in some cases also between subspecies of the same species. Our 3D morphometric analysis shows that the four genetically distinct Giraffa spp. also have distinct cranial morphologies, largely addressable to features of display (ossicones). Our results highlight the importance of focusing future giraffe conservation efforts on each taxon to maintain their unique characteristics and biodiversity in the wild.
长颈鹿（Giraffa spp.）在解剖学、系统发育和生态学方面是现存最为独特的哺乳动物之一。然而，它们的进化、个体发育和分类学方面仍未得到解决，遗留的问题对其保护至关重要。我们收集了已知最大的长颈鹿头骨数据集（n = 515），使用三维几何形态测量学来研究颅骨变异模式。结果显示，北方类群（G. camelopardalis antiquorum、G. c. camelopardalis、G. c. peralta和G. reticulata）和南方类群（G. giraffa angolensis、G. g. giraffa、G. tippelskirchi tippelskirchi和G. t. thornicrofti）存在明显的两性异形以及颅骨形状不同的个体发育轨迹，这在统计学上得到了进一步支持。判别函数发现，所有四种长颈鹿物种之间以及在某些情况下同一物种的亚种之间在颅骨形状上存在统计学上的显著差异。我们的三维形态测量分析表明，四种基因不同的长颈鹿物种也具有不同的颅骨形态，这在很大程度上可归因于展示特征（角状骨）。我们的结果强调了未来长颈鹿保护工作聚焦于每个分类单元以在野外维持其独特特征和生物多样性的重要性。
