uropeltis woodmasoni , commonly known as wood-mason 's earth snake , is a species of snake in the family uropeltidae .

the species is endemic to india .

uropeltis woodmasoni

silybura wood - masoni theobald 1876 : 135 silybura melanogaster günther 1875 ( non uropeltis melanogaster gray 1858 ) silybura nigra beddome 1878 silybura nigra — beddome 1886 : 12 silybura nigra — boulenger 1893 : 151 uropeltis wood - masoni — smith 1943 uropeltis ruhunae deraniyagala 1954 uropeltis ruhunae — mcdiarmid , campbell & touré 1999 : 151 uropeltis woodmasoni — mcdiarmid , campbell & touré 1999 : 151 uropeltis woodmasoni — das 2003 uropeltis ruhunae — wallach et al . 2014 : 782 uropeltis woodmasoni — wallach et al . 2014 : 782
silybura macrorhyncha beddome 1877 silybura macrorhyncha — beddome 1886 : 19 silybura macrorhynchus — boulenger 1893 : 153 uropeltis macrorhynchus — smith 1943 : 78 uropeltis macrorhyncha — mcdiarmid , campbell & touré 1999 : 146 uropeltis macrorhynchus — das 2003 uropeltis macrorhyncha — wallach et al . 2014 : 766
on the taxonomic status of uropeltis bicatenatus ( günther ) ( reptilia : serpentes : uropeltidae ) .
rajendran ( 1985 ) is not convinced that this is a distinct species from uropeltis smithi gans , 1966 .
olori , j . c . 2010 . digital endocasts of the braincase and osseous labyrinth of uropeltis woodmasoni ( alethinophidia : uropeltidae ) . copeia 2010 ( 1 ) : 14 - 26 .
the splenial and angular do not differ substantially from those of u . woodmasoni .
uropeltis is the most speciose of all shieldtail snake ( uropeltid ) genera , particularly in india , a . . .
the angular and splenial have the same general morphology of those of u . woodmasoni .
taxonomic reassessment of two indian shieldtail snakes in the < i > uropeltis ceylanicus < / i > species grou . . .
to cite this page : dr . jennifer olori , c . j . bell , the university of texas at austin , 2012 ,
uropeltis woodmasoni
( on - line ) , digital morphology . accessed july 9 , 2018 at urltoken
{ author1 , author2 . . . } , ( n . d . ) . uropeltis woodmasoni ( theobald , 1876 ) . [ online ] india biodiversity portal , species page : { name of species field } available at : urltoken [ accessed date jul 10 , 2018 ] .
as in u . woodmasoni , the teeth terminate posteriorly at the angular - splenial suture . eight teeth are present .
justification : uropeltis woodmasoni has been assessed as least concern as it is common in parts of its range and there are no known major threats affecting it . in addition , its distribution range coincides with several protected areas . research is needed to establish its population status in parts of its distribution .
the pterygoid is robust and smooth and has a cylindrical ectopterygoid process with a more rounded tip ( fig . 7a ) . the palatine process is also much more robust than in any other species of uropeltis or rhinophis we surveyed . as in u . woodmasoni , curvature toward the otic region is smooth and lacks a pronounced bend .
the quadrate is distinct from that of other rhinophis and uropeltis species examined in having a more sharply pointed caudal process and an anterodorsal corner that is more rounded and lacks a well - developed , triangular extension .
the angular reaches the posterior half of the coronoid process and has a small , ventral foramen . the foramen found in the splenial is located closer to the angular - splenial suture than in species of uropeltis and rhinophis .
the angular lacks the ventral convexity observed in u . woodmasoni . instead , that surface of the bone is rough and irregular and has an anteroposteriorly aligned , low ridge along the midline . medial to the ridge is a dent that may contain a nearly closed foramen at its center . the splenial is like that of u . woodmasoni .
in dorsal view , the nasals appear to be slightly broader than in u . woodmasoni and taper anteriorly only at their tips ( fig . 6a ) . the nasals do not extend as far anteriorly as they do in u . woodmasoni , terminating well posterior to the expansion of the rostral process of the premaxilla . the lateral suture with the septomaxilla is more horizontal than in articulated uropeltis specimens . the suture with the frontal is rounded along its central portion , with distinct lateral processes posteriorly , and small medial processes directed posteriorly between the frontals . no disarticulated material is available .
in ventral view , the palatine has a rounded anterior vomerine process as in u . woodmasoni and most other taxa we examined ( fig . 21g ) . the lateral process , which is again the ventral surface of a closed loop , has a hooked morphology . the loop extends farther laterally than in the examined species of rhinophis and uropeltis , and this structure has a noticeably angled corner at its widest point ( fig . 21g , h ) . unlike in u . woodmasoni the loop does not form right angles with the ventral floor and the lateral surface of the palatine .
the quadrate of u . rubromaculata does not differ substantially from that of u . woodmasoni . however , in articulated skulls , because there is less constriction of the retroarticular process of the compound bone in u . rubromaculata , the shaft appears longer relative to the caudal process , but the proportions are actually the same as in u . woodmasoni .
as in u . rubromaculata , the angular extends to the midpoint of the coronoid process of the compound bone . the splenial does not differ from that of u . woodmasoni .
the posterior end of the dentary is much more pointed than in u . woodmasoni , and the last tooth occurs at the splenial - angular suture . seven teeth are present .
the single specimen possesses a quadrate with a caudal process that is approximately 2 . 5 times the length of the shaft . overall the bone is robust , as in u . woodmasoni .
the occipital condyle of u . woodmasoni has a long , robust neck ( figs . 5a ; 23 ) . posterior to the trough leading down into the braincase , at the narrowest point of the neck , the dorsal surface of the occipital condyle has a shallow depression or fovea for the continuation of the brainstem [ 17 ] . this is also visible in the other species of uropeltis and in rhinophis ( figs . 5a , b ; 6 ) .
the nasals have a broader dorsal surface than in u . woodmasoni ( fig . 5b ) . tapering of the nasals in dorsal view begins farther anteriorly and in lateral view occurs at a much shallower angle , forming a triangular point anteriorly rather than the curved edge seen in u . woodmasoni ( fig . 2b ) . this is associated with the more blunt appearance of the tip of the snout in u . rubromaculata . in addition , in lateral view the ventral surface is less emarginated than in u . woodmasoni . the contact with the frontal is subtly angled posterolaterally and has fine - scale undulations along the suture .
the angular extends posteriorly to below the center of the coronoid process . clear foramina occur in both the angular and splenial , and the foramen in the angular is located more ventrally than in u . woodmasoni .
the anterior rostrum is broader than that of u . woodmasoni , as are the sagittal groove and the portion of the nasal process that separates the nasals ( fig . 5b ) . contact with the vomers does not differ substantially from u . woodmasoni . the subnarial foramen is enclosed entirely within the premaxilla on the right side , but on the left the posterior margin is formed by the palatal tubercle of the septomaxilla ( fig . 4b ) . the contact with the maxilla is relatively broader than in u . woodmasoni , owing mostly to the proportionally broader transverse process of the premaxilla . in palatal view , the vomer is excluded from contact with the maxilla and the transverse process of the premaxilla by a significant exposure of the septomaxilla . a mediolaterally oriented canal penetrates the septum at the base of the nasal process ( as in some specimens of u . woodmasoni ) . the ventral premaxillary foramen is formed as in u . woodmasoni , but an additional small foramen is situated anterior to the former foramen , entering dorsally into the body of the rostrum .
overall , the compound bone strongly resembles that of u . woodmasoni . the retroarticular process , however , is much more rounded and circular , although its dorsal surface does not seem to constrict the socket for the quadrate . a small , thin coronoid bone is present , and in lateral view a foramen is ventral to the anterior half of the coronoid process , although it is located more ventrally than in u . woodmasoni .
synonymy : s . melanogaster günther 1875 is a secondary junior homonym of uropeltis melanogaster gray 1858 . it is hence unavailable und therfore has been replaced by the next available name by gans 1966 . u . ruhunae was synonymized with u . woodmasoni by pyron et al . 2016 . distribution : the locality of ruhunae is likely in error . although it was reported from sri lanka ( galle district , southern province ) with its type locality : „galle
, ceylon , pyron et al . 2016 are almost certain it doesn’t occur there .
the shape , structure , and associations of the frontal in the articulated skull are similar to those outlined for u . woodmasoni , although the crista trabecularis ends posterior to the frontal - parietal suture . disarticulated material is not available .
the ectopterygoid process of the pterygoid is broader and more rounded than that of u . woodmasoni , and reaches half the length and twice the width of the associated palatine process . the angle between the two is greater than 45° .
the ectopterygoid strongly resembles that of u . woodmasoni , but possesses a larger surface area for contact with the maxilla ( the maxilla covers more than half the length of the ectopterygoid ; fig . 6a ) and is also less strongly arched .
the ectopterygoid is similar to that of u . woodmasoni , although the element is slender and somewhat irregular , as in u . melanogaster . however , in dorsal view , the posterior half is not as wide as in u . melanogaster .
the ectopterygoid appears irregular and weakly developed compared to the other uropeltis taxa ( fig . 22b ) . the curvature of the bone forms a sharper ( though still obtuse ) angle , but does not form a lateral flange as in u . rubromaculata . the posterior half of the ectopterygoid is broader horizontally and more dorsoventrally compressed than the anterior half .
uropeltis ceylanica is a nonvenomous shield tail snake species found in southern india . no subspecies are currently recognized . = = geographic range = = found in southern india in the western ghats ( kerala ) from castle rock to travancore ( anaimalai hills ) , in the eastern ghats in the shevaroy hills , and in the southern ghats from kunjithanni ( idikki d . . .
the ectopterygoid is more arched than that of u . woodmasoni in lateral view . the curvature of the bone is also more prominent , forming a more acute and abrupt angle . the apex is slightly expanded laterally to form a small triangular flange ( fig . 5b ) .
the shape and proportions of the maxilla in lateral view differ in u . rubromaculata . more than half the length of the bone tapers posteriorly . the portion of the bone anterior to the ascending process is dorsoventrally much deeper than in u . woodmasoni , giving the ( false ) impression that the anterior portion has been anteroposteriorly compressed ( fig . 2b ) . the ventral margin of the maxilla in lateral view is more strongly irregular than in u . woodmasoni . at the contact with the premaxilla , the lateral surface extends below the ventral margin of the premaxilla .
the maxilla resembles that of u . woodmasoni in lateral view , with a horizontal , unsloped dorsal surface anterior to the ascending process ( fig . 8 ) . the process is narrower than in u . woodmasoni and more rounded at its apex . additionally , the anteriormost foramen is more posteriorly located and the anterior tip of the maxilla is slightly taller , extending ventrally just past the ventral margin of the premaxilla in lateral view . seven tooth positions occupy each side , and the posteriormost tooth is positioned at the level of the anterior - most contact with the ectopterygoid .
the ectopterygoid is straighter than that of u . woodmasoni and r . homolepis , but has a slight bend just posterior to the contact with the maxilla . little of the bone is free of contact with either the pterygoid or the maxilla , and that portion is only slightly arched in lateral view .
other than a smoother and straighter process for the compound , a more sharply pointed posterior tip , and the possession of less edentulous space posterior to the anterior tip , the dentary does not differ substantially from that of u . woodmasoni ( fig . 28i , j ) . eight teeth are present .
the nasals most closely resemble those of u . woodmasoni in proportions and shape . the lateral suture with the septomaxilla is more horizontal . the suture with the frontal is straight but angled obliquely ( fig . 6b ) , because the lateral edge of the nasal extends farther posteriorly than does the medial edge .
rhinophis drummondhayi resembles u . woodmasoni in the length and breadth of the frontals , but the lateral curvature is not as pronounced in dorsal view , and the contact with the prefrontal is curved as in u . rubromaculata . the crista trabecularis ends a short distance anterior to the ventrolateral frontal - parietal suture .
the long , posterior palatine process is dorsoventrally compressed ( figs . 4c ; 16h , i ) and much broader than in u . woodmasoni . the tapering of the posterolateral margin of the vomer that produces the process is more gradual than in u . woodmasoni . in dorsal view , a crest and anterior concavity occur in association with the posterolateral process as in other taxa ( fig . 16g ) . a single dorsal foramen pierces the posterolateral crest near its origin at the medial wall . dorsal to the palatine process , a short , tapered , and pointed additional posterior process begins at the medial wall ( fig . 16g , i ) . in between the two posterior processes , a small , anteroposteriorly directed canal leads into the medial wall . the canal exits at the level of the crest , in the floor of the medial wall and , based on position , may be homologous to the ventral foramen of u . woodmasoni .
the ectopterygoid shows less curvature than that of u . woodmasoni . a slight , dorsally convex arch characterizes the bone in lateral view . a subtle apex , formed by the transition between the laterally compressed anterior half and the dorsoventrally compressed posterior half of the element , occurs immediately posterior to the contact with the maxilla .
in u . woodmasoni , the ectopterygoid process is dorsoventrally compressed anteriorly . the angle formed at the junction of the ectopterygoid and palatine processes is approximately 45° , and the ectopterygoid process is usually between one - quarter and one - half the length of the palatine process ( fig . 22e ) . in ventral view , about three - quarters of the way from anterior to posterior , the pterygoid curves and bends laterally toward the otic region . in lateral view the element shows a dorsally convex arch , sloping upward from the lowest position at the posterior end to the highest point at the anterior end . the posterior tip of the pterygoid is spatulate in u . woodmasoni .
in dorsolateral view , the wide , anterior portion of the palatine extends laterally only to the lacrimal duct , falling short of the terminus of the maxillary process of the prefrontal . in addition to the tiny foramen visible in this view in u . woodmasoni , a second foramen is located at the posterior extent of the contact with the maxilla , near the base of the pterygoid process . when viewed laterally , the tapering of the pterygoid process and the end of contact with the frontal occur anterior to the optic foramen , farther anteriorly than in u . woodmasoni . the clasping articulation of the pterygoid process of the palatine with the palatine process of the pterygoid is depicted in figure 17b .
the dentary has a much more sharply pointed posterior tip than that of u . woodmasoni , and the teeth end posteriorly at the splenial - angular suture . the groove for meckel ' s cartilage is open in anterior view , and this creates a medial , trochlea - like expansion of the anterior tip of the dentary . eight teeth are present .
the coronoid process of the compound bone is broad , and somewhat triangular . a foramen pierces the medial surface of the retroarticular process , but none occurs ventral to the coronoid process . the retroarticular process is like that of u . woodmasoni , and both the dorsal portion of the process and the anterior rim of the socket for the quadrate constrict the cotyle .
in ventral view the anterior edge of the vomer has a short , ventral premaxillary process with a shallow , lateral indentation and farther laterally a tiny , pointed projection that juts between the premaxilla and septomaxilla ( figs . 4b ; 17b ) . the anterior margin of the anterolateral process is posterior to that projection . compared to u . woodmasoni , the anterolateral process is expanded and has a squared appearance . the anterolateral process of the vomer and the anteromedial process of the maxilla do not touch but both are in contact with the overlying septomaxilla . within the vomeronasal opening , a thin bar of bone separates the smaller , medial half from the lateral half . as in u . woodmasoni , u . rubromaculata has a long , thin palatine process .
as in u . woodmasoni , the maxilla and ectopterygoid of u . rubromaculata have a long mediolateral contact , with the maxilla lateral to the ectopterygoid . however , in u . rubromaculata the posterior rim of the posteriormost tooth position coincides with the beginning of the contact with the ectopterygoid . in ventral view , the palatine process is broader , larger , and more rounded medially than in u . woodmasoni ( fig . 4b ) . the maxilla and vomer do not contact in palatal view . the teeth are much larger and fewer in number than in any other taxon examined ( six positions on the left , five on the right ) . our tooth count is consistent with a previous report of five maxillary teeth in u . rubromaculata [ 15 ] .
the supraorbital processes are robust and similar to those of u . woodmasoni , but the sagittal crest is stronger and terminates anteriorly at a triangular , roughened , shallow depression . there is only a small posterior notch along the midline . in lateral view , the majority of the cn v 2 foramen is in the braincase , and the parietal completes only the anterior - most portion .
the prefrontal is not as anteroposteriorly shortened as in r . blythii , nor is it as round as in u . woodmasoni ( fig . 8b ) . in this specimen ( tmm m - 10046 ) the prefrontal and parietal closely approach , but do not actually contact , one another . the rounded inflection of the anterodorsal margin is located at the junction with the nasal and septomaxilla .
the frontals are proportionately wider and shorter than in the uropeltis specimens . the contacts in the articulated skull are the same , although sharper and more angled than in r . blythii . in dorsal exposure , a small , pointed process appears to jut into the junction of the frontal with the prefrontal and supraorbital process of the parietal and may occur because the prefrontal and supraorbital process are in contact . a similar , but narrower , surface extends into the junction between frontal , nasal , and prefrontal . the crista trabecularis ends at the frontal - parietal suture .
the basioccipital and basisphenoid are fused in all of our adult specimens , although previously those bones were reported to remain separate [ 17 ] . thus , this species exhibits the same degree of fusion found in rhinophis and uropeltis . dorsally , no sagittal crest occurs in the supraoccipital region . the canals piercing that area are more medially positioned than they are in species of uropeltis and rhinophis and open posteriorly inside the dorsal margin of the foramen magnum . the occipital condyle is short , lacking any solid neck between the triangular trough leading into the braincase and the actual condyle , and there is no posterior fovea as exhibited by uropeltis and rhinophis ( figs . 5c , 27 ) . the number of hypoglossal openings varies individually in b . rhodogaster . in tmm m - 10019 , tmm m - 10027 , and tmm m - 10022 there are two on the right and one on the left , whereas in tmm m - 10016 , tmm m - 10023 , and tmm m - 10020 there are two on the left and one on the right . in tmm m - 10013 , tmm m - 10017 , tmm m - 10018 , tmm m - 10024 , and tmm m - 10014 the opening is single on both sides , and in tmm m - 10015 , tmm m - 10026 , and tmm m - 10020 it is paired on both sides . when paired , one opening is located dorsal to the other , and the more dorsal opening is smaller . an exception occurs in specimen tmm m - 10011 , in which the opening is single on the right , but on the left it appears to be paired as a result of a deep division of one large foramen .
the supraorbital processes are straight and slender , with little tapering and a shorter length relative to the other species we examined ( fig . 8a ) . dorsally the sagittal crest is stronger than in the three uropeltis species examined and ends anteriorly at a weakly depressed , roughened , irregular spot . the two lobes of the shelf dorsal to the otic region are relatively short , and there is a small , squared notch at the posterior midline . in lateral view the cn v 2 opening is almost entirely within the braincase , but a small portion of the parietal completes its anterior edge .
anterior is to the left unless noted ; scale bars = 0 . 5 mm . a from u . woodmasoni ( tmm m - 10001 ) ; b from u . melanogaster ( tmm m - 10045 ) ; c from b . rhodogaster ( tmm m - 10027 ) ; and d–f from ct scans of u . woodmasoni ( tmm m - 10006 ) . left quadrates in lateral view ( a–c ) , and right stapes in ventrolateral ( k , anterior to the right ) , dorsal ( l , anterior to the right ) , and anterolateral ( m , lateral to the left ) views . fp . st = stapedial footplate ; m . con = mandibular condyle of quadrate ; sh . st = stapedial shaft ; sst . p = suprastapedial process ( caudal process ) of quadrate ; urltoken = tympanic crest of quadrate .
the posteromedial corner of the nasal buttress completely encloses the vomeronasal posteromedial foramen , forming a short tube ( visible only in the disarticulated element , fig . 10i , l ) . the posteromedial process associated with this foramen is short and triangular in b . rhodogaster . the open , posterior margin of the cupola for the vomeronasal organ is rounded and upswept , as opposed to the condition in u . woodmasoni and u . melanogaster .
the ectopterygoid process is narrow , and the palatine process is slender ( fig . 7b ) . the ectopterygoid process is less than a quarter of the length of the palatine process . the angle between the processes is slightly less than 45° , and their junction occurs farther anteriorly than in uropeltis , approximately one - quarter of the way from the anterior end of the bone . a distinct bend with a roughly square flange or extension is placed at the point where the posterior tip curves upward toward the otic region . this occurs three - quarters of the way down the bone , moving from anterior to posterior .
the nasals are more rectangular than in species referred to either uropeltis or rhinophis . tapering occurs only at the anteromedial tip and is visible only in dorsal view ( figs . 5c , 12g ) . the overall appearance is of a rectangular bone with an anterolateral notch . the nasal process of the premaxilla is exposed in the narrow space between the anterior ends of the nasals . in lateral view , the nasal shares an elongated contact with the septomaxilla ; no dorsal emargination is present , but the posterior margin of the external naris excavates a shallow notch in the anterior surface of the nasal ( figs . 2c , 12h ) .
the ventral premaxillary process is small and rounded , abuts the vomerine process of the premaxilla , and possesses a shallow indentation laterally ( figs . 7b ; 18b ) . the anterolateral process is squared and meets the anteromedial process of the maxilla . the anterior projection of the posterolateral process forms much more of the vomeronasal opening than in any other species examined . the small , pointed process that projects into the vomeronasal opening originates dorsal to the ventral surface , rather than at it as in the three species of uropeltis , and r . blythii . dorsally , the vomer has a strong medial inflection . the palatine process is not elongate .
the posterior part of the transverse process of the premaxilla slots into the space between the anteromedial process and the anterior tip of the maxilla ( fig . 3i ) , forming a clasping articulation between the two elements . in palatal view , the entire anterior surface of the anteromedial process forms a firm articulation with the transverse process of the premaxilla ( unlike in u . woodmasoni , in which only a small lateral portion of the anterior surface contacts the premaxilla ) .
the dentary is similar to that of u . woodmasoni , except in the case of the teeth , which extend farther posteriorly ; two full sockets are located posterior to the angular - splenial suture . eight teeth occur on the dentary ; like the maxillary teeth , they are enlarged relative to those of other taxa examined ( fig . 2b ) . our tooth count is higher than a previous report of six or seven dentary teeth occurring in specimens of u . rubromaculata [ 15 ] .
the contact of the prefrontal with the nasal in lateral view is longer than in u . woodmasoni , and the inflection in the shape of the anterodorsal margin occurs ventral to the junction with the nasal and septomaxilla . as in u . melanogaster , the lateral surface appears anteroposteriorly compressed , and overall the bone is taller than it is long ( fig . 8a ) . the frontal process is much larger than the lateral foot process , but does not contact the supraorbital process of the parietal .
in lateral view , the entire dorsal margin of the compound bone is arched from the posterior extent of the dentary articulation to just anterior to the articulation with the quadrate , forming a large , broad , rounded coronoid process ( fig . 8a ) . this gives the compound bone a wide and smooth appearance at its midpoint . a tiny coronoid bone is present , but unlike in u . woodmasoni , a sliver of the bone is visible in lateral view along the dorsal margin of the compound bone .
when the six characters that exhibited the highest degree of polymorphism and individual asymmetries ( i . e . , characters 4 , 6 , 7 , 11 , 13 ) were removed from the analysis , 469 mpts were recovered ( tree length = 49 , ci = 0 . 7755 , ri = 0 . 8791 ) . as indicated by the majority rule consensus ( fig . 29b ) , a clade comprising species of uropeltis , rhinophis , and plectrurus was recovered in most topologies ( 87 % ) . however , in both the majority rule and strict consensus , resolution of relationships other than the position of species of melanophidium was extremely poor , suggesting that the excluded characters carry phylogenetic signal and should be revised rather than discarded ( figs . 29b , 30b ) .
the parietal is a smoothly rounded , dorsally convex , midline element . at its anterolateral margin , a fingerlike supraorbital process extends anteriorly onto each frontal . in addition to the frontal , the parietal contacts the fused braincase complex posteriorly and ventrally , and occasionally the prefrontal anteriorly ( via the supraorbital process ) . the parietal closely approaches the pterygoid laterally , but soft tissue prevents contact . in all uropeltids we examined , only a single , unpaired parietal is present , although previous authors reported that incomplete fusion of the parietals is visible in some specimens of rhinophis and uropeltis [ 17 ] . it seems likely that those reports were based on the narrow , slit - like opening along the posterior midline of the parietal visible in some specimens ( e . g . , fig . 15 ) .
both specimens resemble u . woodmasoni in their frontal proportions , but as in the other rhinophis species we examined , the frontals show much less mediolateral tapering in dorsal view . the crista trabecularis ends just anterior to the frontal - parietal suture . in all rhinophis species examined the optic foramen was contained within the frontal . in tmm m - 10038 , the palatal bones are disarticulated , and it is clear that the posterior bifurcation of the ventral groove is absent . in tmm m - 10037 the frontal process of the prefrontal and the supraorbital process of the parietal are in contact .
the supraorbital processes of the parietal are proportionately narrower and straighter than in u . woodmasoni , and also are less tapered anteriorly . in dorsal view , the sagittal crest is more strongly developed in u . rubromaculata , but still weak , and the crest ends at a circular , roughened patch of bone instead of terminating at a depression . the posterior margin of the parietal has a prominent trilobed appearance . in lateral view , the opening for the cn v 2 is almost entirely within the braincase , but the anterior margin is completed by the parietal ( fig . 2b ) .
in one specimen ( tmm m - 10032 ) , the caudal process is proportionately longer than the shaft , reaching 2 . 5 times the length of the latter . the second specimen , tmm m - 10045 , lacks this extra length and shows a stronger resemblance to u . woodmasoni , although both specimens of u . melanogaster have a more slender quadrate ( fig . 25b ) . the anterodorsal margin of the quadrate curves so that the anterodorsal corner is ventral to the dorsal margin of the bone . the angle between the caudal process and the shaft is more acute , roughly 90° .
the anterolateral process is large , broad , and squared in ventral view . it meets the anteromedial process of the maxilla and maintains contact with it along the posterior margin of the latter , moving toward the body of the maxilla . the anterior margin of the vomer is more like that of u . woodmasoni than r . blythii . it is also similar to those taxa in that the small process that projects into the vomeronasal opening originates on the ventral surface of the bone . as in all other rhinophis species we examined , the palatine process is not elongate ( figs . 7d ; 19b ) .
the maxilla more closely resembles that of u . woodmasoni than r . blythii in lateral view , because the anterior tip does not extend ventrally past the premaxilla at the suture between the two elements , but the maxilla does deepen just posterior to that suture ( fig . 8b ) . the posteriormost lateral foramen is entirely anterior to the ascending process . in ventral view , the palatine process is small and does not extend far medially ( fig . 7b ) . seven tooth positions occur on each side , and the posteriormost tooth is positioned at the level of the anterior - most contact with the ectopterygoid .
in anterolateral view the dorsal premaxillary process of the vomer extends anteriorly past the septomaxilla and is visible in the floor of the external naris . in ventral view , the triangularly pointed ventral premaxillary process of the vomer lies lateral to the vomerine process of the premaxilla ( figs . 7a ; 18a ) . the medial surface of the premaxillary process is l - shaped and receives the vomerine process of the premaxilla . posterolaterally , the anterolateral process of the vomer contacts the anteromedial process of the maxilla on the right side , but not the left side , of our specimen ( tmm m - 10030 ) . the posterolateral process and its anterior projection are broader and rounder than in the other species of uropeltis examined . the posterolateral process is thickened and a small ridge occurs where the process forms the posterolateral margin of the vomeronasal opening . the palatine process is not elongate .
the prefrontal is similar to that of u . woodmasoni , but has a relatively larger frontal process that is also larger than the lateral foot process . in lateral view the rounded inflection in the anterodorsal margin occurs just posterior to the junction with the nasal and septomaxilla . a clear gap separates the frontal process of the prefrontal and the supraorbital process of the parietal . additionally , the entire anterior half of the ventrolateral margin ( including the medial foot process ) is overlapped by the ascending process of the maxilla , so that no part of the prefrontal is visible between the septomaxilla and the ascending process of the maxilla .
as in the other rhinophis , the anterior lateral foramen of the maxilla is positioned more posteriorly than in u . woodmasoni . the lateral maxillary foramina are proportionately larger than any other taxon surveyed . the posterior - most foramen is located ventral and slightly posterior to the midpoint of the ascending process ( fig . 8d ) . ventrally , the anteromedial process is reduced , and the palatine process has a triangular , posteriorly directed point ( fig . 7d ) . the vomer and maxilla contact in palatal view . there are seven tooth positions on each side , and the posteriormost tooth is positioned just anterior to the anteriormost contact with the ectopterygoid .
the shape of the septomaxilla is similar to that of u . woodmasoni in lateral view , but is more rounded overall . in lateral exposure , its anterior margin curves so that the ventral portion extends farther anteriorly than the dorsal ( fig . 8a ) . the septomaxilla reaches its anteriormost extent at the level of the premaxilla - maxilla suture and contacts both bones at that suture . there is no palatal tubercle visible between the junction of the vomer , premaxilla , and maxilla . the vomer and maxilla meet in palatal view because of complete underlap of the septomaxilla by the vomers and a robust anteromedial process of the maxilla ( fig . 7a ) .
anterior is to the left ; scale bars = 1 . 0 mm . ( a ) u . woodmasoni , tmm m - 10010 . note missing max , pl , ecpt , and pt on left side . ( b ) u . rubromaculata , tmm m - 10028 . note that right lower jaw is present . ang = angular ; den = dentary ; ecpt = ectopterygoid ; fr = frontal ; max = maxilla ; pal . tub = palatine tubercle of septomaxilla ; pfr = prefrontal ; pl = palatine ; pmx = premaxilla ; pt = pterygoid ; smx = septomaxilla ; spl = splenial ; sph = sphenoid region of the otooccipital complex ; vo = vomer .
anterior up ; scale bars = 1 . 0 mm . ( a ) u . woodmasoni , tmm m - 10006 ; ( b ) u . rubromaculata , tmm m - 10028 ( c ) b . rhodogaster , tmm m - 10011 . ecpt = ectopterygoid ; fr = frontal ; low . j = lower jaw ; max = maxilla ; na = nasal ; oo . c = otooccipital complex ; pa = parietal ; pfr = prefrontal ; pmx = premaxilla ; pl = palatine ; pt = pterygoid ; smx = septomaxilla ; q = quadrate ; r . c = rieppel ' s canal ; v2m . f = foramen for branch of maxillary branch of trigeminal nerve .
anterior is to the left ; scale bar = 0 . 5 mm . a–c from u . woodmasoni ( tmm m - 10001 ) ; d–f from u . melanogaster ( tmm m - 10045 ) ; and g–i from b . rhodogaster ( tmm m - 10022 ) . a , d , g in dorsal view ; b , e , h in ventral view ; and c , f , i in lateral view . arrow points to slit - like opening along posterior midline of parietal . urltoken = parietal shelf ; s . o . p = supraorbital process of the parietal ; tab = tab - like process that articulates with otic region ; v2 . f = notch that contributes to v2 foramen .
the premaxilla is similar to that of r . blythii , but the rostrum is more rounded and less broad ( similar to the condition in u . woodmasoni ) . the contact with the maxilla in lateral view is almost vertical , but a small posterodorsal tip of the transverse process of the premaxilla overlaps the anterior portion of the dorsal margin of the maxilla ( fig . 8d ) . the vomerine process is emarginated in a way similar to that of r . drummondhayi . the subnarial opening is completely enclosed by the premaxilla on the right side , but a small portion of the septomaxilla closes the opening on the left ( fig . 7d ) . a single ventral premaxillary foramen and a foramen piercing the medial septum are present .
anterior is to the left in a , d , e ; anterior is to the right in b , c , f ; scale bar = 0 . 5 mm . a–c from the left side of the skull in u . woodmasoni ( tmm m - 10001 ) ; d–f from the right side of the skull in u . melanogaster ( tmm m - 10045 ) ; and g–i from the left side of the skull in b . rhodogaster ( tmm m - 10027 ) . a , c , e in lateral view and b , d , f in medial view . fr . pfr = frontal process of prefrontal ; knob = medially projecting knob at base of frontal process of prefrontal ; l . f . p = lateral foot plate ; m . f . p = medial foot process .
anterior is to the right unless noted ; scale bars = 0 . 5 mm . a , e from u . woodmasoni ( tmm m - 10001 ) ; b , f from u . melanogaster ( tmm m - 10045 ) ; c , d from b . rhodogaster ( tmm m - 10016 ) ; and g from b . rhodogaster ( tmm m - 10022 ) . right ectopterygoids in ventral ( a–c ) and dorsal ( d ) views ; left pterygoids ( e , g ; anterior to the left ) and right pterygoid ( f ) in dorsal views . ect . pt = ectopterygoid process of pterygoid ; mx . ect = maxillary process of ectopterygoid ; pl . pt = palatine process of pterygoid ; post . p = posterior process of pterygoid ; pt . ect = pterygoid process of ectopterygoid .
anterior is to the left unless noted ; scale bar = 0 . 5 mm . all elements from the left side of the skull . a–c from u . woodmasoni ( tmm m - 10001 ) ; d–f from u . melanogaster ( tmm m - 10045 ) ; and g–i from b . rhodogaster ( tmm m - 10022 ) . a , d , g in dorsal view ; b , e , h in lateral view ; and c , f , i in medial view ( anterior is to the right ) . can = anterior opening of the canal within the medial process of the nasal ; md . p = medial process ; pmx . na = premaxillary process of nasal ; shelf = shelf that is continuous with pre - orbital ridge of frontal ; vl . p = ventrolateral process at triple junction .
the openings for cn v 2 and cn v 3 are in the same positions as in u . woodmasoni , although the prootic canal is shifted dorsally and appears to be merged with the juxtastapedial recess . the canal is separated from the opening of the v 3 by a narrow partition of bone . on the left side the laterosphenoid foramen is ventral to and between the openings for cn v 2 and cn v 3 , but on the right it is located posterodorsally , adjacent to the anteroventral margin of the cn v 3 foramen . a tiny dorsal metotic foramen is visible when viewed through the foramen magnum , and the opening for cn x and the jugular vein is single . the opening for the hypoglossal nerve also is single . the interchoanal process is visible , but because the specimen is articulated , it is unknown if that process extends anteriorly beyond the cultriform process .
anterior up ; scale bars = 1 . 0 mm . ( a ) u . woodmasoni , tmm m - 10006 ; ( b ) u . rubromaculata , tmm m - 10028 ; ( c ) b . rhodogaster , tmm m - 10011 . ang = angular ; com = compound ; den = dentary ; ecpt = ectopterygoid ; js . r = juxtastapedial recess ; max = maxilla ; oo . c = otooccipital complex ; pa = parietal ; pl = palatine ; pmx = premaxilla ; pro . c = prootic canal ; pt = pterygoid ; smx = septomaxilla ; spl = splenial ; sub . f = subnarial foramen ; q = quadrate ; vn . o = vomeronasal opening ; vo = vomer ; vp . f = ventral premaxillary foramen ; v2 . f = foramen for maxillary branch of trigeminal nerve ; v3 . f = foramen for mandibular branch of trigeminal nerve .
anterior is to the left in a–f ; anterior is to the right in i ; scale bar = 0 . 5 mm . a–c from the right side of u . woodmasoni ( tmm m - 10001 ) ; d–f from the right side of the skull of u . melanogaster ( tmm m - 10045 ) ; and g–i from the left side of the skull of b . rhodogaster ( tmm m - 10022 ) . a , d , g in dorsal view ; b , e , h in ventral view ; and c , f , i in medial view . ch . pl = choanal process of palatine ; lat . f = tiny lateral foramen ; lat . p = lateral process of palatine ; pt . pl = pterygoid process of palatine ; vo . pl = vomerine process of palatine ; v2m . f = foramen for branch of the trigeminal nerve ( cn v 2 ) .
the pterygoid has a higher arch in lateral view and more curvature in dorsal view than in u . woodmasoni . the bend originates earlier , approximately halfway along the bone from anterior to posterior . a broad , short flange or extension of the apex of curvature occurs posterior to the center of the pterygoid ( fig . 22f ) . the ectopterygoid process is short , approximately one - quarter the length of the palatine process . the anteriormost tip of the palatine process is irregular . the palatine process is wide at its base , but gradually tapers anteriorly . the process becomes dorsoventrally compressed on its lateral side near its base , giving the impression of a thin sheet ( i . e . , web ) of bone between the palatine and ectopterygoid processes . at about three - quarters of the distance anteriorly , the tapering becomes abrupt and the resulting tip is pointed and slender . the posterior process is rounded .
anterior is to the left ; scale bar = 0 . 5 mm . a–c from u . woodmasoni ( tmm m - 10001 ) ; d–f from u . melanogaster ( tmm m - 10045 ) ; and g–i from b . rhodogaster ( tmm m - 10024 ) . a , d , g in dorsal view ; b , e , h in ventral view ; and c , f , i in lateral view . the posterior tip of the nasal process is broken in the b . rhodogaster specimen . l . f = lateral foramen ; na . pmx = nasal process ( keel ) of premaxilla ; pl . c = posterolateral canal ; ros = rostral tip ; sep . c = septal canal ; sub . f = subnarial foramen ; sub . fen = subnarial fenestra ; trv . p = transverse process ; vp . f = ventral premaxillary foramen ; vo . pmx = vomerine process of premaxilla .
the vertical suture with the braincase complex terminates dorsally at a broad shelf of the parietal that extends posteriorly to overlie the anterodorsal half of the otic capsules , in the supraoccipital region . the lateral edges of the shelf are straight and horizontal and originate at a right angle to the vertical suture with the otic region . in other taxa the posterior extent of the shelf is composed of two short , oblate lobes , but in u . woodmasoni the lobes are broad and meet along the posterior midline to form a rounded , smooth , and upswept posterior margin . in three specimens ( tmm m - 10001 , - 10004 , - 10009 ) , the posteriormost region of the shelf butterflies into a small v - shaped notch along the midline ( fig . 15a ) . in disarticulated specimens the ventral surface of the posterior shelf is rough and irregular along the area where it articulates with the otic capsules ( fig . 15b ) .
anterior is to the left unless noted ; scale bar = 0 . 5 mm . all elements from the left side of the skull . a–c from u . woodmasoni ( tmm m - 10001 ) ; d–f from u . melanogaster ( tmm m - 10045 ) ; and g–i from b . rhodogaster ( tmm m - 10022 ) . a , d , g in dorsal view ; b , e , h in lateral view ; and c , f , i in medial view ( anterior is to the right ) . fr . c = frontal canal ; l . f . f = lateral frontal flange ; m . f . f = mesial frontal flange ; o . f = optic foramen ; ol . fr . = olfactory process of frontal ; p . o . r = pre - orbital ridge of frontal ; so . g = groove for supraorbital process of parietal ; trab . g = groove for cartilaginous portion of crista trabecularis .
anterior is to the left in a–f ; anterior is to the right in i ; scale bar = 0 . 5 mm . a–c from the right side of u . woodmasoni ( tmm m - 10001 ) ; d–f from the right side of u . melanogaster ( tmm m - 10045 ) ; and g–i from the left side of b . rhodogaster ( tmm m - 10022 ) . a , d , g in dorsal view ; b , e , h in ventral view ; and c , f , i in medial view . al . p = anterior lateral process ; d . pmx . vo = dorsal premaxillary process of vomer ; dm . f = dorsomedial foramen of posterolateral crest ; md . w = medial wall ; urltoken = crest on posterolateral process ; pl . p = posterior lateral process ; pl . vo = palatine process of vomer ; pmx . vo = premaxillary process of vomer ; tab = bone tab projecting into vomero - nasal opening ; v . pmx . vo = ventral premaxillary process of vomer .
anterior is to the left unless noted ; scale bar = 0 . 5 mm . all elements from the left side of the skull . a–c from u . woodmasoni ( tmm m - 10001 ) ; d–f from u . melanogaster ( tmm m - 10045 ) ; and g–i from b . rhodogaster ( tmm m - 10022 ) . a , d , g in lateral view ; b , e , h in medial view ( anterior is to the right ) ; and c , f , i in dorsal view . a . m . f = anterior maxillary foramen ; alv . c = alveolar canal ; ant . med . p = anteromedial process ; asc . mx = ascending process ; ect . mx = ectopterygoid process of maxilla ; f . jug + x = foramen for jugular vein and vagus nerve ; m . m . f = middle maxillary foramen ; p . m . f = posterior maxillary foramen ; pl . mx = palatine process ( posteromedial process ) of maxilla ; pmx . mx = premaxillary process of maxilla ; shelf = shelf medial to articulation facet for prefrontal .
in ventral view , the lateral process of the palatine [ 32 ] projects anterolaterally towards the posterior margin of the palatine process of the maxilla , by which it is underlapped . in dorsolateral view of articulated skulls , and even more clearly in disarticulated specimens , it can be seen that the lateral ‘process’ is the ventral surface of a loop of bone surrounding the large foramen for cn v 2 ( fig . 21b ) . the same structure was described for the disarticulated palatine of p . aureus [ 19 ] . in u . woodmasoni , the loop is oriented vertically and aligned anterolaterally from its origin on the lateral surface of the palatine , positioned at right angles to the ventral floor and the lateral wall of the element . in some specimens the presence of a suture indicates that the loop is formed by closure between a dorsally reaching ventrolateral process and a ventrally reaching dorsolateral process . when disarticulated and viewed ventrally , anterior to the loop and at the exit for the foramen , a broad groove or depression slopes anteroventrally , eventually flattening out with the ventral surface of the palatine . the palatine process of the maxilla articulates with this groove ( fig . 21b ) .
in u . woodmasoni , the nasals contact each other medially along a straight suture from their posterior contact with the frontals until approximately three - quarters of their length anteriorly ( fig . 5a ) . at the point of overlap with the premaxilla , the premaxillary processes of the nasals diverge laterally . the nasal process of the premaxilla is visible dorsally as a wedge located in the fork between the two nasals . the nasals overlap the premaxilla up to the point where the rostral process of the premaxilla expands laterally . in both dorsal and lateral views , the nasal tapers anteriorly ( figs . 2a ; 5a ; 12a , b ) . in lateral view , a broad , crescentic ventral emargination forms the dorsal border of the external naris . in most specimens , the emargination begins at the anterior point of contact with the septomaxilla and increases in a gradual curve anteriorly . in tmm m - 10003 , tmm m - 10005 , and tmm m - 10010 , the emargination begins anterior to that contact . the anterolateral extent forms a rounded surface with a slight ventral inclination ( fig . 2a ) ; dorsally the anterior end of the nasal appears as an elongated , pointed premaxillary process .