Abstract:
African wild dogs (Lycaon pictus) are unique among canids in their specialized hunting strategies and social organization. Unlike other, more omnivorous canids, L. pictus is a hypercarnivore that consumes almost exclusively meat, particularly prey larger than its body size, which it hunts through cooperative, exhaustive predation tactics. Its bite force is also among the highest reported for carnivorans. Here, we dissected an adult male L. pictus specimen and conducted diffusion iodine contrast-enhanced computed tomography (diceCT) scans to evaluate and describe its masticatory and oral cavity musculature. Muscles of mastication in L. pictus are separated by deep layers of thick intermuscular fascia and deep insertions. The superficial surface of m. masseter is entirely covered by an extremely thick masseteric fascia. Deep to m. masseter pars reflexa and superficialis are additional bellies, m. masseter pars profunda and zygomaticomandibularis. Musculus temporalis in L. pictus, divides into suprazygomatic, superficial, and deep bellies separated by a deep layer of thick intermuscular fascia, and it inserts along the entire rostral margin of the mandibular ramus. Musculus digastricus appears to comprise a single, large fusiform belly which appears to receive its innervation exclusively from CN V3 (nervus mandibularis, division of nervus trigeminus). Musculus pterygoideus medialis and lateralis are each composed of a single, deep belly. However, despite its great bite force, the jaw adductor muscle mass in L. pictus is not increased for its body size over other canid taxa. This finding suggests there are other architectural adaptations to hypercarnivory beyond increased muscle volume (e.g., pennation angle, greater strength, optimization of lever arms for mechanical advantage).
摘要:
非洲野狗(Lycaonpictus)在其专门的狩猎策略和社会组织中在犬科动物中是独一无二的。不像其他人,更多杂食性犬科动物,L.pictus是一种食肉动物,几乎只消耗肉类,尤其是大于其体型的猎物,它通过合作社猎杀,详尽的捕食策略。它的咬合力也是食肉动物报道的最高之一。这里,我们解剖了成年男性L.pictus标本,并进行了扩散碘对比增强计算机断层扫描(diceCT)扫描,以评估和描述其咀嚼和口腔肌肉组织。P.pictus的咀嚼肌肉被深层的厚肌间筋膜和深层插入物隔开。m.咬肌的表面完全被极厚的咬肌筋膜覆盖。深至米咬肌的反射和肤浅是额外的腹部,m。皮氏乳杆菌的颞肌,分为上骨,肤浅的,深腹被一层厚厚的肌间筋膜隔开,它沿着下颌支的整个鼻缘插入。digastricus似乎由一个人组成,大梭形腹部似乎仅从CNV3(神经神经,三叉神经的分裂)。中侧翼状肌和外侧肌各由一个组成,深沉的肚子.然而,尽管它的咬合力很大,与其他犬科类群相比,皮氏乳杆菌的颌骨内收肌质量没有增加。这一发现表明,除了增加肌肉体积之外,还有其他建筑适应于高食肉性(例如,悬念角度,更大的力量,优化杠杆臂的机械优势)。