Morphological Features of <scp>H</scp>erbst Corpuscles in the Oropharynx of the Ostrich (<scp>S</scp>truthio camelus) and Emu (<scp>D</scp>romaius novaehollandiae)

2015

Zoomorphology

This study, facilitated by the use of immunohistochemistry, indicated the presence of taste buds in Dromaius novaehollandiae but not in Struthio camelus. Seen at the light microscope level, the taste buds consisted of follicular cells and receptor cells. The follicular cells were located at the periphery of the taste bud, essentially encapsulating the receptor cells. Two morphologically distinct receptor cells were identified. Immunohistochemical labelling for neurofilament identified gustatory nerves within the taste bud. The distribution of taste buds in D. novaehollandiae matched strategic locations in the oropharynx along which food could be sampled, according to the feeding method described for these birds. Future feeding studies would be necessary in D. novaehollandiae to determine the importance of taste discrimination in their diet. This study represents the first confirmed report of a sense of taste in any ratite species.

Section: Immunohistochemistrymentioning

confidence: 99%

Contrasting morphological evidence for the presence of taste buds in Dromaius novaehollandiae and Struthio camelus (Palaeognathae, Aves)

2015

Zoomorphology

“…More recently, the bill tip of ratite species has received particular attention, initially in the Apterygidae where a bill tip organ was described in five extant kiwi species (Cunningham et al, 2013;Cunningham, Castro, & Alley, 2007). Subsequently, aspects of the rostral bill tips have been studied in the ostrich (Struthio camelus) and emu (Dromaius novaehollandiae) with regards to the bony bill tip (Crole & Soley, 2017), the branches of the trigeminal nerve supplying this region (Crole & Soley, 2016) and the distribution (Crole & Soley, 2014) and structure (Crole, du Plessis, & Soley, 2015) of Herbst corpuscles.…”

Section: Introductionmentioning

confidence: 99%

Persistence of Meckel's cartilage in sub‐adult Struthio camelus and Dromaius novaehollandiae

2018

Acta Zoologica

This study describes the persistence of an embryonal structure through to sub‐adulthood in the ostrich and emu. Mandibles from sub‐adult ostrich and emu were subjected to special staining, light microscopy and dissected to reveal and describe Meckel's cartilage. Meckel's cartilage, composed of hyaline cartilage, was present within the neurovascular canal of both species. The persistence through to sub‐adulthood of Meckel's cartilage in the ostrich and emu is a feature not previously reported in any other avian species. The proximal end of Meckel's cartilage was ossified in the region of the articular bone and the distal end was ossified in some specimens. Although this structure may ossify at a much later stage in life, the function in young and sub‐adult birds may be to dampen shockwaves along the intramandibular nerve that result from the action of pecking. In the ostrich, the M. pseudotemporalis superficialis tendon inserted onto the supra‐angular bone and Meckel's cartilage. In the emu, a small portion of the tendon was attached to the supra‐angular bone and the main part to Meckel's cartilage. The persistence of Meckel's cartilage in adult lepidosaurs, crocodilians and ratites represents an unusual shared trait between the extant members of the above groups.

“…The sketches of Parker () and digital images available on the internet (Dodd, ; Franzosa, ) of the ostrich and emu skull similarly reveal numerous small, bony pits in the bill tip although they are not specifically identified as such. Herbst corpuscle structure (Crole et al, ) and their distribution in the oropharynx of the ostrich and emu (Crole and Soley, ) has been described. Additionally, the bill tip is richly innervated (Crole and Soley, ).…”

Section: Introductionmentioning

confidence: 99%

Bony Pits in the Ostrich (Struthio camelus) and Emu (Dromaius novaehollandiae) Bill Tip

2017

The Anatomical Record

Self Cite

A specialized region of the bill tip characterized by a complex arrangement of mechanoreceptors and referred to as a bill tip organ, has been identified in numerous avians. A bill tip organ was initially inferred in kiwi species by the presence of numerous, bony pits in the rostrum of the bill, and later confirmed histologically. This study enumerates and compares the number and distribution of pits present in the bill tip in the ostrich and emu. The heads from 10 ostrich and 5 emu were prepared for osteological examination. The pattern and total number of pits was similar between the two species. However, the ostrich had significantly more pits in the regions underlying the Culmen and Gonys, whereas the emu displayed significantly more pits in the dorsal part of the mandibular rostrum. The relatively even distribution of pits in the inner and outer surfaces of both the mandibular and maxillary rostra suggest that the bill tip of the ostrich and emu are equally sensitive externally and intra-orally, as opposed to probing birds, where the major concentration of pits is located on the outer surfaces of the bill tips. The presence of pits in the bill tips of extant paleaognaths may be of relevance in interpreting the pits in the rostra of extinct therapod dinosaurs. The presence of bony pits in a region which is also well supplied with sensory nerves is highly suggestive of a bill tip organ in the ostrich and emu and which needs to be confirmed histologically. Anat Rec, 300:1705-1715, 2017. © 2017 Wiley Periodicals, Inc.