Abstract The mammalian rostrum has multiple functions including serving as the upper jaw, supporting olfactory sensory structures, conditioning inspired air, and—for some mammals—transmitting sound. Several groups of bats independently evolved bony inflations on the dorsolateral surfaces of their rostra. In rhinolophoid bats, rostral inflations are associated with nasal emission of echolocation calls, but their function in oral emitting bats (family Emballonuridae) is not well understood. Here, we combine μCT, diceCT, and histological methods to describe and quantify nasal fossa morphology of emballonurid bats in a comparative sample of 24 species overall, including 23 in the quantitative CT sample. Our goals are to (1) describe and quantify paranasal recess morphology, (2) explore scaling of paranasal recess size with body, skull, main nasal chamber, and turbinal size, (3) elucidate potential functions of rostral inflations in emballonurids, and (4) understand how nasal fossa morphology is related to presence of socially important glands and odor storing sacs in Emballonuridae. We report surprising diversity, clade‐specific traits, and several novelties in paranasal recess size and location among emballonurids. The combined volume of the paranasal recesses and main nasal chamber was more strongly correlated with peak echolocation call frequency used during foraging than with skull size. Some emballonurid species possess a well‐developed lateral nasal gland in the lateral recess. Other emballonurids have inflated, air‐filled paranasal recesses lined with thin, avascular mucosa, similar to those of nasal emitters with rostral inflations. We also observed turbinal traits reminiscent of those in nasal emitting Rhinolophidae. Proportionally large paranasal recesses are associated with reduced size and turbinal elements in emballonurid bats, except possibly in species that exhibit complex mating displays using perfume storing sacs in their wing membranes. Together, our results suggest that paranasal recesses could play a role in modifying echolocation calls in Emballonuridae, as they are hypothesized to do in nasophonating bats. However, the potential acoustic function of paranasal recesses remains to be experimentally elucidated in bats.
Cartilaginous fish have diverse morphological traits that are essential for understanding their evolutionary history and ecological adaptations. However, the conus arteriosus and its valves, key components of the heart and blood circulation, have been underexplored in phylogenetic and ecomorphological contexts. Here, we (1) characterize the morphological diversity and distribution of conal valves across Chondrichthyes, (2) evaluate the phylogenetic signal of valve characters and their potential usefulness for understanding evolutionary relationships, and (3) test whether variation in valve morphology is associated with lifestyle and locomotor demands. Our results show that the number of valves, as well as their distribution along the conus arteriosus, is generally consistent with the pattern observed in previous studies of two to seven rows of valves, with predominantly three series. Novel findings include a higher number of valve rows (up to six) than previously found in sharks and the first detailed descriptions for the orders Torpediniformes and Squatiniformes. Our results indicate that conal morphology is weakly correlated with phylogeny, but is strongly associated with locomotor demands and lifestyle.
Ardea alba (Linnaeus, 1758) is widely distributed, yet knowledge of its ocular morphology remains limited. This study described the morphometry and morphology of the eyeball and its accessory glands in six specimens using radiography, morphometry, light and scanning electron microscopy, and 3D scanning. The eyeballs showed similar descriptive morphometric values in the right and left eyes, accounting for approximately 11.2% of head mass and 12.12% of total skull length. The eye was classified as the flat type, a morphology previously associated in the literature with diurnal birds, featuring a yellow iris and a circular pupil. The scleral ring consists of 14 bilateral type A ossicles associated with hyaline scleral cartilage. Histologically, the cornea showed a well-defined Bowman's membrane, and the retina had 10 distinct layers. The pleated type pecten emerged from the optic nerve and extended toward the vitreous body. The accessory glands were characterized as follows: the Harderian gland (type II) was the most developed; the lacrimal gland was "hockey-stick" shaped; and the nasal gland (salt gland) was supraorbital in location and pyramidal in appearance. These results provide a robust anatomical basis for comparative avian ophthalmology.
