Jaw musculature of the Meiglyptini (Aves: Piciformes: Picidae)

Abstract

The Meiglyptini comprise eight species of woodpeckers grouped into three genera, two of which contain three species ( Meiglyptes and Mulleripicus), while one genus includes two species ( Hemicircus). The purpose of this study is to describe the mandibular apparatus found in six species of Meiglyptini and to compare them with each other and with other woodpecker species. The results reveal a number of structures that are worth mentioning: (i) the components of the external mandibular adductor system of Hemicircus concretus, particularly the M. adductor mandibulae externus caudalis medialis, are underdeveloped compared with the other investigated species; (ii) the muscles of the internal mandibular system are structurally different among Meiglyptes species and are less developed, both in size and in structure, in H. concretus; (iii) the M . protractor quadrati is vestigial in Meiglyptes species; (iv) the muscles of the protractor system of the quadrate are relatively undeveloped in H. concretus; (v) most of the muscles of the pterygoideus system are structurally differentiated in Meiglyptes species. It appears that the complexity of the mandibular apparatus is associated with the type of food consumed, as the apparatus of the frugivorous species H. concretus is markedly different from that of the insectivorous species.

Cranial Osteology of Meiglyptini (Aves:Piciformes:Picidae)

“…oticus quadrati and clearly has dorsal, lateral, medial, and ventral faces. This is the region of origin of the aponeurosis of the M. adductor mandibulae externus ventralis and the M. adductor mandibulae externus rostralis lateralis (Donatelli, [ 5 ]). The Proc.…”

“…Between the cristae ventralis et lateralis lies the fossa ventralis (FV), which is distinct and deep in M. tristis ( Figure 10 ), relatively deep and shallow in species of Mulleripicus ( Figure 11 ), and shallow in M. tukki ( Figure 12 ) and H. concretus ( Figure 9 ). This is an important region because it is the origin of the aponeurosis and muscle fibres of the M. pterygoideus ventralis (Donatelli, [ 5 ]).…”

“…The Os laterosphenoidale lies caudally to the facies orbitales . It is connected laterally with the Os squamosum by the crista laterosphenoidale (CrL– Figure 5 ), where the aponeurosis of the M. adductor mandibulae externus caudalis medialis originates (Donatelli, [ 5 ]). This crest is apparent only in species of the genus Mulleripicus and in M. tukki ( Figure 5 ).…”

“…In the proc. oticus quadrati , a small C1 crest (C1Cr) can be observed in all species but represented in M. tristis ( Figure 4 ), which originates from the aponeurosis of the M. adductor mandibulae externus caudalis lateralis (Donatelli, [ 5 ]). The proc.…”

Relationship Between Jaw Apparatus, Feeding Habit, and Food Source in Oriental Woodpeckers

“…In addition to the structural differences in the components of the mandible musculature in Meiglyptini species (Donatelli, 2012b), there are a few other notable characteristics: 1) the components of the external mandibular adductor system of H. concretus, particularly the M.a.m.e. caudalis medialis, are relatively poorly developed compared to other species; 2) Meiglyptes spp.…”