Share this post on:

Ertebrae ([15]; pers.obs.). Immediately posterior to the abrupt transition, the anterior neomorphic vertebrae have a single row of Thonzonium (bromide) manufacturer elements that probably represent the centra. The regenerated vertebrae located further posteriorly, however, exhibit two rows of elements, likely the neural arches and centra. Carroll and Gaskill ([1] reference figure 81F) illustrated the same pattern for an additional specimen of M. pelikani that I did not examine. In non-regenerated tails, the caudal vertebrae remain relatively large posteriorly, even bmjopen-2015-010112 as they approach the soft-tissue tip of the tail (Fig 16B). Pectoral Girdle and Forelimb. journal.pone.0077579 The dermal elements of the pectoral girdle, cleithrum, clavicle, and interclavicle, ossify early [16] and are relatively unchanged during growth. In contrast to a previous description, but in agreement with an illustration from the same study ([1] reference figure 120G), the clavicle has a relatively broad, paddle-like blade with a lightly sculptured or roughened ventral surface (Fig 17A). The width of blade that is visible depends on the get DS5565 orientation of the clavicle as preserved. The interclavicle of M. pelikani has distinct fimbriations anteriorly, although that morphology is also present in H. longicostatum and the lepospondyl Sparodus validens, also from N ny ([1]; pers.obs.). In M. pelikani, the fimbriations are elongate and gracile (Fig 17B), and are present in the smallest individual possessing an interclavicle, which is not surprising considering that the bone is not pre-formed in cartilage. In all specimens examined, the length of the interclavicle stem is approximately one-third the width of thePLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,25 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 16. Tail regeneration in M. pelikani. A. MB.Am.815, showing regenerated tail segment; anterior to the left; plaster cast. B. NHMW1894-2332, showing posterior tip of tail in bone and outlined as skin impression; anterior to the right. Note relatively large size of terminal vertebrae. Scale bars = 1mm. doi:10.1371/journal.pone.0128333.ginterclavicle plate. A cluster of small, round foramina or pits commonly is located dorsal to the interclavicle stem. In larger individuals, the posterior processes flanking the interclavicle stem may elaborate into long curved or bifurcate structures (Fig 17B). In M. pelikani, the scapula ossifies late relative to the rest of the postcranial elements [16]. The three smallest specimens that clearly possess an ossified scapula all have a skull length of 17mm. In those individuals, the element is relatively small and has an irregular `D’ or subcircular shape (Fig 17C). In larger specimens, the D-shape becomes even more pronounced and the scapula exhibits a robust, thickened ridge around its curved edge (Fig 17D). The glenoid, however, is still not well developed, although its location is visible. One of the largest individuals, MB.Am.17 (same specimen as MB.Am.822), was figured by Carroll and Gaskill ([1] referencePLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,26 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 17. Pectoral girdle of M. pelikani. A. M1681, clavicle; ventral view, bone/impression. B. CGH142, interclavicle; ventral view, anterior up, bone. C. St.198, scapula; ventral view, anterior up, medial left, bone/impression. D. NHMW1983_32_49a, scapula; ventral view, anterior up, bone/impression. E. MB. Am.17, scapula; ventral view, anterior to the left, medial u.Ertebrae ([15]; pers.obs.). Immediately posterior to the abrupt transition, the anterior neomorphic vertebrae have a single row of elements that probably represent the centra. The regenerated vertebrae located further posteriorly, however, exhibit two rows of elements, likely the neural arches and centra. Carroll and Gaskill ([1] reference figure 81F) illustrated the same pattern for an additional specimen of M. pelikani that I did not examine. In non-regenerated tails, the caudal vertebrae remain relatively large posteriorly, even bmjopen-2015-010112 as they approach the soft-tissue tip of the tail (Fig 16B). Pectoral Girdle and Forelimb. journal.pone.0077579 The dermal elements of the pectoral girdle, cleithrum, clavicle, and interclavicle, ossify early [16] and are relatively unchanged during growth. In contrast to a previous description, but in agreement with an illustration from the same study ([1] reference figure 120G), the clavicle has a relatively broad, paddle-like blade with a lightly sculptured or roughened ventral surface (Fig 17A). The width of blade that is visible depends on the orientation of the clavicle as preserved. The interclavicle of M. pelikani has distinct fimbriations anteriorly, although that morphology is also present in H. longicostatum and the lepospondyl Sparodus validens, also from N ny ([1]; pers.obs.). In M. pelikani, the fimbriations are elongate and gracile (Fig 17B), and are present in the smallest individual possessing an interclavicle, which is not surprising considering that the bone is not pre-formed in cartilage. In all specimens examined, the length of the interclavicle stem is approximately one-third the width of thePLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,25 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 16. Tail regeneration in M. pelikani. A. MB.Am.815, showing regenerated tail segment; anterior to the left; plaster cast. B. NHMW1894-2332, showing posterior tip of tail in bone and outlined as skin impression; anterior to the right. Note relatively large size of terminal vertebrae. Scale bars = 1mm. doi:10.1371/journal.pone.0128333.ginterclavicle plate. A cluster of small, round foramina or pits commonly is located dorsal to the interclavicle stem. In larger individuals, the posterior processes flanking the interclavicle stem may elaborate into long curved or bifurcate structures (Fig 17B). In M. pelikani, the scapula ossifies late relative to the rest of the postcranial elements [16]. The three smallest specimens that clearly possess an ossified scapula all have a skull length of 17mm. In those individuals, the element is relatively small and has an irregular `D’ or subcircular shape (Fig 17C). In larger specimens, the D-shape becomes even more pronounced and the scapula exhibits a robust, thickened ridge around its curved edge (Fig 17D). The glenoid, however, is still not well developed, although its location is visible. One of the largest individuals, MB.Am.17 (same specimen as MB.Am.822), was figured by Carroll and Gaskill ([1] referencePLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,26 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 17. Pectoral girdle of M. pelikani. A. M1681, clavicle; ventral view, bone/impression. B. CGH142, interclavicle; ventral view, anterior up, bone. C. St.198, scapula; ventral view, anterior up, medial left, bone/impression. D. NHMW1983_32_49a, scapula; ventral view, anterior up, bone/impression. E. MB. Am.17, scapula; ventral view, anterior to the left, medial u.

Share this post on:

Author: Potassium channel