Finally, we propose two possible scenarios for the maxilloturbinal development: 1) the maxilloturbinal of talpids and soricids became small independently with a limited number of lamellae as a result of convergent evolution, or 2) the common ancestor of talpids and soricids already had a small and simple maxilloturbinal. The epiturbinal at the ethmoturbinal II disappeared in soricids independently. The nasoturbinal of the common ancestor of talpids and soricids was most likely rostrocaudally elongated. Although the turbinal and lamina morphology was previsouly considered to be similar among eulipotyphlans, we found phylogenetic patterns for talpids and soricids. We observed various fetuses and adults of talpids and soricids using high-resolution diffusible iodine-based contrast-enhanced computed tomography (diceCT) and reviewed previous reports on erinaceids, solenodontids, and other laurasiatherians. In this regard, investigation on fetal anatomy and ontogenetic changes of the nasal capsule allows us to evaluate the homologies of the turbinals and laminae. The inner structure of the nasal cavity of mammals is highly complicated and the homologies of the turbinals among mammalian species are still largely unsettled. Their resolved phylogenetic relationships now allow us to revisit the turbinal and lamina evolution of this group. The phylogenetic relationships of major groups within the Order Eulipotyphla was once highly disputed, but the advent of molecular studies has greatly improved our understanding about the diversification history of talpids, soricids, erinaceids, and solenodontids. This observation supports an accelerated development in the golden hamster. Maturity of Mesocricetus auratus that has the shortest gestation period among placental mammals corresponds to that of other altricial resemble generally theĭevelopmental pattern of altricial muroids although e.g., paries nasi resorption starts clearly earlier in Acomys. Surprisingly, the precocial Sigmodon hispidus and Acomys sp. The paries nasi and tectum nasi are almost completely resorbed except for the anterior nasal cartilages and those parts that become ossifiedĪnd part of the ethmoid bone (e.g., roots of turbinals). In around 14 days old stages of some investigated muroids Start around birth and follow a distinct pattern observed in many other rodents. However, in muroids resorption of the nasal capsule and ossification of the turbinals, nasal septum and lamina cribrosa already Perinatal stages of all altricial muroid species under study have a less mature ethmoidal region compared to precocial rodents e.g., caviomorphs. Sylvaticus, Micromys minutus, Mus musculus, and Rattus norvegicus.
Apomorphic patternsĪre restricted to the number of turbinals in the frontoturbinal recess: three in Abrothrix longipilis, one in Apodemus flavicollis, Apodemus
Olfactory turbinals (two frontoturbinals, three ethmoturbinals, one interturbinal between the first two ethmoturbinals). The muroid grundplan of the ethmoidal region is already determined at birth and comprises a general pattern of six In addition adult crania of selected Muroidea Were investigated, some of which are represented by more than one ontogenetic stage.
#Mus2 serial serial#
Perinatal transformation of the nasal capsule histological serial sections of 23 muroid species, one dipodid species, and two geomyoid species This is especially the case in the most species-rich rodent group, the Muroidea. However, the perinatal development of the ethmoidal region is not well studied though this is aĬraniogenetic crucial time frame. A deeper understanding of the early ontogeny of the ethmoidal region helps to elucidate morphological patternsĪnd homologies in the adult cranium.
The cartilaginous nasal capsule of mammals becomes highly modified during ontogeny by resorption and ossification that finally results
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