Of which is, thus, excluded from the external naris. As reflected in previously published Thin Plate Splines (TPS; [17]), the anterolateral edge of the nasal that curves posteriorly around the naris to form the lacrimal process becomes relatively shorter in Cycloheximide site larger individuals, suggesting that the diameter of the naris decreases proportionately as well. The only other change exhibited by the nasal is a transition from angular to rounded edges Beclabuvir web during growth. A similar change occurs in the frontals, which start out with relatively straight margins in small specimens, but the margins become more sinuous with increased growth (Fig 8). In the smallest specimen, the parietal also has relatively straight margins in addition to a less laterally extensive lateral lappet (Fig 9A). In larger individuals, the sutures become increasingly sinuous and, as reflected in TPS analysis [17], the lateral lappet expands in size (Fig 9B). In most specimens, regardless of size, the pineal foramen is relatively large and located closer to the frontal-parietal suture than to the postparietal-parietal suture. Traditional morphometrics suggested that there is a great deal of individual, rather than ontogenetic, variation in both the location and size of the pineal [17]. Contra Vallin and Laurin [9], a pineal is clearlyPLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,12 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 7. Narial region in M. pelikani. Dorsal view of bones in St.200, anterior is up, lateral to the right. Top image includes line drawing interpretation of sutures observed in original photograph (bottom). Fr, frontal; La, lacrimal; Mx, maxilla; N, naris; Na, nasal; Or, orbit; Pmx, premaxilla. Scale bar is in 1 mm increments. doi:10.1371/journal.pone.0128333.gvisible in all pnas.1408988111 specimens in which poor preservation is not a factor. The specimen that Vallin and Laurin [9] suggested to be lacking a pineal (MB.Am.815 (Museum f Naturkunde, Leibniz-Institut f Evolutions- und Biodiversit sforschung, Berlin, Germany); Fig 2B) is actually a modified plaster cast that exhibits many errors in the emphasis of sutures and the shape of cranial elements. Carroll and Gaskill [1] noted that the dorsal exposure of the postparietal increases with growth. Mistakenly applying that observation to the entire wcs.1183 dorsal lamina (versus the occipital portion), including the anterior margin that underlies the parietal, Vallin and Laurin [9] did not observe an ontogenetic trend. I do not agree with either previous interpretation and suggest that the dorsal exposure of the dorsal flange tends to be proportionately smaller in larger individuals, although there is much individual variation and possibly deformation resulting from crushing of the occipital flange. Likely contributing to the past discrepancy is the tendency forPLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,13 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 8. Shape change in the frontal during development of M. pelikani. Arrows point to lateral line pits. A. Small individual, NHMW1893_32_66. Dorsal view, anterior up. B. Medium individual, M1700. Dorsal view, anterior up. C. Large individual, St.201. Dorsal view, anterior up. Fr, frontal; Mid, midline suture; Na, nasal; Or, orbit; Pa, parietal; Pfr, prefrontal; Pn, pineal foramen. Scale bars = 1mm. doi:10.1371/journal.pone.0128333.gthe sculpture on the parietal and postparietals to knit together, obscuring the suture between the two elements. However.Of which is, thus, excluded from the external naris. As reflected in previously published Thin Plate Splines (TPS; [17]), the anterolateral edge of the nasal that curves posteriorly around the naris to form the lacrimal process becomes relatively shorter in larger individuals, suggesting that the diameter of the naris decreases proportionately as well. The only other change exhibited by the nasal is a transition from angular to rounded edges during growth. A similar change occurs in the frontals, which start out with relatively straight margins in small specimens, but the margins become more sinuous with increased growth (Fig 8). In the smallest specimen, the parietal also has relatively straight margins in addition to a less laterally extensive lateral lappet (Fig 9A). In larger individuals, the sutures become increasingly sinuous and, as reflected in TPS analysis [17], the lateral lappet expands in size (Fig 9B). In most specimens, regardless of size, the pineal foramen is relatively large and located closer to the frontal-parietal suture than to the postparietal-parietal suture. Traditional morphometrics suggested that there is a great deal of individual, rather than ontogenetic, variation in both the location and size of the pineal [17]. Contra Vallin and Laurin [9], a pineal is clearlyPLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,12 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 7. Narial region in M. pelikani. Dorsal view of bones in St.200, anterior is up, lateral to the right. Top image includes line drawing interpretation of sutures observed in original photograph (bottom). Fr, frontal; La, lacrimal; Mx, maxilla; N, naris; Na, nasal; Or, orbit; Pmx, premaxilla. Scale bar is in 1 mm increments. doi:10.1371/journal.pone.0128333.gvisible in all pnas.1408988111 specimens in which poor preservation is not a factor. The specimen that Vallin and Laurin [9] suggested to be lacking a pineal (MB.Am.815 (Museum f Naturkunde, Leibniz-Institut f Evolutions- und Biodiversit sforschung, Berlin, Germany); Fig 2B) is actually a modified plaster cast that exhibits many errors in the emphasis of sutures and the shape of cranial elements. Carroll and Gaskill [1] noted that the dorsal exposure of the postparietal increases with growth. Mistakenly applying that observation to the entire wcs.1183 dorsal lamina (versus the occipital portion), including the anterior margin that underlies the parietal, Vallin and Laurin [9] did not observe an ontogenetic trend. I do not agree with either previous interpretation and suggest that the dorsal exposure of the dorsal flange tends to be proportionately smaller in larger individuals, although there is much individual variation and possibly deformation resulting from crushing of the occipital flange. Likely contributing to the past discrepancy is the tendency forPLOS ONE | DOI:10.1371/journal.pone.0128333 June 17,13 /Skeletal Morphogenesis of Microbrachis and HyloplesionFig 8. Shape change in the frontal during development of M. pelikani. Arrows point to lateral line pits. A. Small individual, NHMW1893_32_66. Dorsal view, anterior up. B. Medium individual, M1700. Dorsal view, anterior up. C. Large individual, St.201. Dorsal view, anterior up. Fr, frontal; Mid, midline suture; Na, nasal; Or, orbit; Pa, parietal; Pfr, prefrontal; Pn, pineal foramen. Scale bars = 1mm. doi:10.1371/journal.pone.0128333.gthe sculpture on the parietal and postparietals to knit together, obscuring the suture between the two elements. However.
