hyopsodus is a genus of extinct odd-toed ungulate mammal of the family hyopsodontidae .

fossils of this genus have been found in north america , especially the bighorn basin region of the united states .

it is believed to have been swift and nimble , living in burrows , and perhaps able to use echolocation .

hyopsodus

endocast measurements for hyopsodus ( given in mm , and mm 3 for endocast volume ) .
development of the corpora quadrigemina in ( a ) hyopsodus , ( b ) rhinolophus hipposideros , ( c ) tenrec ecaudatus .
hyopsodus ( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming . american museum novitates ; no . 3007
dental measurements of amnh 143783 referred to hyopsodus lepidus ( given in mm ) . measurements are base don the 3d reconstruction of the dentition .
figure 1 . hyopsodus as originally reconstructed ( below ) and as reconstructed here above in two views . this former condylarth now nests with dogs .
figure 2 . miacis , an eocene ancestor to extant dogs , such as canis . note the transverse premaxilla and tiny premaxillary teeth as in hyopsodus .
details - hyopsodus ( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming . american museum novitates ; no . 3007 - biodiversity heritage library
citation : orliac mj , argot c , gilissen e ( 2012 ) digital cranial endocast of hyopsodus ( mammalia , “condylarthra” ) : a case of paleogene terrestrial echolocation ? plos one 7 ( 2 ) : e30000 . urltoken
full reference : l . krishtalka . 1979 . paleontology and geology of the badwater creek area , central wyoming . part 18 . revision of late eocene hyopsodus . annals of carnegie museum 48 ( 20 ) : 377 - 389
ty - book ti - hyopsodus ( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming . american museum novitates ; no . 3007 ur - urltoken py - 1991 au - flynn , john j . ( john joseph ) , er -
“hyopsodus presents one of the highest encephalization quotients of archaic ungulates and shows an “advanced version” of the basal ungulate brain pattern , with a mosaic of archaic characters such as large olfactory bulbs , weak ventral expansion of the neopallium , and absence of neopallium fissuration , as well as more specialized ones such as the relative reduction of the cerebellum compared to cerebrum or the enlargement of the inferior colliculus [ hearing ] . the detailed analysis of the overall morphology of the postcranial skeleton of hyopsodus indicates a nimble , fast moving animal that likely lived in burrows . ”
although no strict relationship between echolocation and the development of inferior colliculus has been demonstrated in extant terrestrial mammals , the inferior colliculus size in hyopsodus could indicate that the latter used terrestrial echolocation to investigate subterranean environment and / or to minimize predation during nocturnal exploration of the environment as concluded for extant shrews [ 55 ] – [ 57 ] .
@ book { bhl170947 , title = { hyopsodus ( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming . american museum novitates ; no . 3007 } , url = urltoken note = urltoken publisher = { } , author = { flynn , john j . ( john joseph ) , } , year = { } , pages = { 0 } , }
reconstructions made after the original cranial endocasts of : ( a ) hyopsodus lepidus ( amnh 143783 ) , ( b ) pleuraspidotherium ( mnhn cr 252 , 963 ; cast amnh 39266 ) ; ( c ) phenacodus ( amnh 4369 ) ; ( d ) meniscotherium ( amnh 49082 ; usnm 19509 ) ; ( e ) arctocyon ( mnhn cr 700 ) , modified after russell and sigogneau ( 1965 ) . not to scale . abbreviations : same as .
reconstructions made after the original cranial endocasts of : ( a ) hyopsodus lepidus ( amnh 143783 ) , ( b ) pleuraspidotherium ( mnhn cr 252 , 963 ; cast amnh 39266 ) ; ( c ) phenacodus ( amnh 4369 ) ; ( d ) meniscotherium ( amnh 49082 ; usnm 19509 ) ; ( e ) arctocyon ( mnhn cr 700 ) , modified after russell and sigogneau ( 1965 ) . not to scale . abbreviations : same as figure 2 .
reconstructions made after the original cranial endocasts of : ( a ) phenacodus ( amnh 4369 ) , ( b ) , meniscotherium ( amnh 49082 ) , ( c ) hyopsodus ( amnh 143783 ) , ( d ) pleuraspidotherium ( mnhn cr 252 , 963 ) , ( e ) arctocyon ( mnhn cr 700 ) , ( f ) cebochoerus ( mnhn 34–1967 ) , ( g ) hyracotherium ( amnh 55267 ) . all specimens normalized on the neopallium length . proportions of the different parts indicated in percent of the total endocast length : black , rhinencephalon ; red , neopallium ; blue , mesencephalon ; green , cerebellum . not to scale .
the most significant feature observed in hyopsodus is the clear delineation of the corpora quadrigemina , and especially the large development of the inferior colliculus . the superior colliculus receives major inputs from the retina but is more than just a visual processing structure . one of its major functions is to localize a stimulus and to cause the animal to orient to the stimulus by moving its neck and / or its eyes [ 44 ] . in contrast to the role of the superior colliculus within the visual system , the inferior colliculus is the principal source of input to the auditory thalamus , which relays auditory information to the primary auditory cortex [ 45 ] . moreover , the inferior colliculus probably also represents a major output to premotor pathways that initiate or regulate sound evoked motor behavior [ 46 ] .
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université montpellier 2 , ise - m umr 5554 , montpellier , france . maeva . orliac @ urltoken
pmid : 22347998 pmcid : pmc3277592 doi : 10 . 1371 / journal . pone . 0030000
specimen illustrated in lateral ( a ) , dorsal ( b ) , and ventral ( c ) views . scale bar = 1 cm .
reconstruction illustrated in left lateral ( a ) , dorsal ( b ) , right lateral ( c ) , ventral with basicranium ( d ) , ventral without basicranium ( e ) , and posterior views . abbreviations : cas , cavernous sinus ; cc , condyloid canal ; cdf , condyloid foramen ; ci , colliculi inferior ; cf , condylar foramen ; cs , colliculi superior ; fl , paraflocculus ; flm , foramen lacerum medium ; flp , foramen lacerum posterius ; fo , foramen ovale ; fp , fissure prima ; hy , hypophysis ; ips , inferior petrosal sinus ; lal , lateral lobe of cerebellum ; las , lateral sinus ( or transverse sinus ) ; los , longitudinal sinus ; mf , mastoid foramen ; mo , medulla oblongata ; ms , mesencephalon ; mv , mastoid vein ; np , neopallium ; ob , olfactory bulb ; oc , occipital condyle ; op , olfactory peduncle ; os , occipital sinus ; ot , olfactory tubercle ; pb , petrosal bone ; pgf , postglenoid foramen ; pil , piriform lobe ; rhp , rhinal fissure ; sc , sinusal canal ; tf , temporal foramen ; ts , temporal sinus ; vc , vermis cerebelli . scale bar = 1 cm .
conceived and designed the experiments : mjo . analyzed the data : mjo ca eg . contributed reagents / materials / analysis tools : mjo ca eg . wrote the paper : mjo ca eg .
this is an open - access article distributed under the terms of the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are properly credited .
a major function of the brain is the maintenance of physiological condition ( homeostasy ) . by collecting and processing sensory information , it insures optimal behavioral responses in a given environment . therefore , several brain structures are molded by the ecophysiological situation of the animal within its niche [ 1 ] – [ 4 ] . the increased use of computed tomography ( ctscan ) recently gave an unprecedented access to internal structures of fossils , and triggered new interest for vertebrate cranial endocast studies ( e . g . , [ 5 ] – [ 14 ] ) . these recent works are building upon fundamental studies performed during the second half of the 20 th century ( e . g . , [ 15 ] – [ 20 ] ) and cranial endocast anatomy is now documented for major mammalians clades .
the brain and associated soft tissues such as meninges , nerves , veins and arteries are sheltered in the neurocranium and leave imprints on its tabula interna . the study of the endocranial cast is the only means to reach an understanding about the nervous and sensory system of extinct species . edinger [ 21 ] and jerison [ 17 ] demonstrated that analysis of mammalian endocasts can provide a good approximation of the relative size of the major encephalic subdivisions and accordingly , comparative studies of fossil mammalian endocasts largely contributed to our knowledge of brain evolutionary history ( e . g . , [ 6 ] , [ 17 ] , [ 22 ] – [ 25 ] ) .
in the history of mammals , ‘condylarthra’ consists of a para – or polyphyletic assemblage of paleocene - eocene early diverging ungulates that potentially played a crucial role in the onset of crown ungulate clades such as perissodactyla , artiodactyla , cetacea , proboscidea , sirenia , and hyracoidea ( e . g . ,
) . the diversity of these groups is also reflected in the disparity of brain morphologies . the phylogenetic relationships of archaic ungulates remain a current topic of investigation . a recent hypothesis of relationships among basal ungulates mammals
simplified phylogenetic relationships among basal ungulates , modified after [ 36 , fig . 11b ] .
the braincase of amnh 143783 is broken in two parts at the base of the olfactory bulbs . the two fragments match perfectly and the neurocranium is complete (
) . the skull has undergone a slight dorso - ventral compression and the braincase is slightly deformed by a lateral shift . measurements of the endocast are provided in
) . the vermis of the cerebellum constitutes the highest point of the brain . the cerebrum is relatively flat compared with the cerebellum . the shape of the cerebrum is correlated to the almost complete absence of telencephalic flexure . the maximal width is at the level of the piriform lobes (
the specimen amnh 143783 gives access to the complete extension of the rhinencephalon . the latter is strongly developed , as it almost represents half of the forebrain . the bulging olfactory lobes are of large size . their combined diameters equal the width of the dorsal roof of the skull in the posterior half of the orbits (
) . the two lobes are elongated and contiguous . they are prolonged by long olfactory fibers spreading into the anterior part of the orbits and beyond ( not reconstructed on the 3d model because of bad preservation of the specimen ) . the olfactory bulbs directly extend the olfactory peduncles . both structures are aligned with the rest of the telencephalon . the location of the olfactory tubercles is not clear on the right side of the skull because of postmortem deformation . it is observable on the left side , although weakly prominent (
) . the piriform lobes represent most of the cerebral hemispheres ; they are visible in dorsal view in the posterolateral part of the cerebrum where they constitute the greatest width of the brain . they are dorsally delimited by the posterior rhinal fissure located in the dorsal third of the cerebrum height . a sinus might be present in the posterolateral part of the piriform lobe , but there is no trace of its anterior extension .
, a considerable portion of the forebrain was missing and the telencephalon was only partially described . especially , the location of the rhinal fissure was unknown . in the specimen described here , the posterior rhinal fissure is shallow but clearly present on both sides of the telencephalon (
) . it is located in the dorsal third of the hemisphere and delimits the posteroventral border of the neopallium . the anterior rhinal fissure is difficult to locate . when present , it is limited to the anteriormost part of the cerebrum and does not abut on the posterior rhinal fissure . the neopallium thus forms a reduced cap on the cerebral hemisphere . the neopallium is smooth or lissencephalic , suggesting that there were no gyri or sulci ( neither the lateral sulcus nor the suprasylvian sulcus ) . only a subtle convexity lays on the dorsoposterior part of the neopallium , slightly posterior to the location of the gyrus 3 described in earliest artiodactyls (
; orliac pers . obs ) . this structure marks the highest point of the cerebrum , with its dorsal part being flat and anteriorly sloping . the neopallium is distinctly narrower in its anterior portion . between the medial margins of the neopallium , the longitudinal sinus in
is deep and clearly sets apart the two cerebral hemispheres . the lateral or transverse sinuses separate just ahead of the superior colliculi .
the posterior limit of the neopallium is far apart from the lobes of the cerebellum , and the tectum of the midbrain is broadly exposed on the dorsal surface . the midbrain exposure is accentuated by the anterior divergence of the two cerebral hemispheres .
the corpora quadrigemina ( colliculi ) are clearly visible . the inferior colliculus is especially important , and its development occupies most of the exposed midbrain . this special feature is also observed in the specimen described by gazin [ 35 ] . on x - ray radiographies , quasi perpendicular to the tabula interna , the tentorium cerebelli is a thick crest of bone separating the cerebrum from the cerebellum .
the cerebellum is large and exhibits a well delimited vermis , cerebellar hemispheres ( lateral lobes ) and paraflocculus . the vermis of the cerebellum is wide and elevated ; its dorsal extension is pointed and reaches the same level as the dorsal face of the telencephalon . the fissura prima is located in the posterior third of the vermis . the cerebellar hemispheres are separated from the cerebrum by a broad and shallow paramedian fissure . the former are moderately developed and not inflated , sloping anteriorly . their dorsal surface is almost flat . in dorsal view , their posterior extension does not reach that of the vermis , with the posterior part of the latter forming a wide bulge . on both ventrolateral surfaces , the paraflocculi are observable . they consist of two rounded and large sized lobes that project outwards , downwards and somewhat backwards .
the superior petrosal sinus is located underneath the cerebellar hemispheres , a continuation of the transverse or lateral sinus system . the posterior part of the sinus system cannot be described because most of the occipital surface of the skull is eroded and the bone is not preserved . the anterior part of the lateral sinus system , or temporal sinus , is partially reconstructed in blue on
. it extends ventrally and leads to the postglenoid foramen ( path for the external jugular vein ) . dorsally , it leads to several small foramina indicating vascular communication with the temporal surface . posteriorly , the occipital sinus runs external to the petrosal bone and opens on the occipital surface at the level of the mastoid foramen ( path for the mastoid vein ) . ventrally , the petrosal sinus curves slightly forward to the foramen lacerum posterius ( internal jugular vein ) . just ventral to this flexure , and before the sinus reaches the foramen lacerum posterius , a small posterior sinus corresponding to the condyloid canal opens in the internal aspect of the occipital condyle . posteroventral to it , on the side of the medulla oblongata , lies the condylar foramen ( or hypoglossal foramen ) which corresponds to the path of the nerve xii .
ventromedial to the paraflocullus there is the prominence representing the internal auditory meatus with the cast of the facial nerve ( vii ) , and of the auditory nerve ( viii ) located more posteroventrally . the elongated foramen lacerum medium , medial to the internal auditory meatus , connects posteriorly the foramen lacerum posterius by a discrete inferior petrosal sinus . the foramen ovale lies posterolateral to the cavernous sinus and contains the third branch of the trigeminal nerve ( v
. the corresponding encephalization quotient ( eq ) calculated with an estimated body mass ( em ) of 630 g ( based on head and body length ) , is of 0 . 36 using the equation proposed by jerison
discussed the problem of estimating body weights of archaic ungulates which greatly differ from extant members of the group . indeed , the body shape and proportions of
are markedly different from those of extant ungulates from which the correlations between dental measurements and body weight are estimated , making it difficult to propose plausible estimates . with its elongated body and relatively short limbs ,
regressions for non - selenodont ungulates using m1 area and m1 length . depending of the formula used , the estimated body weight of amnh 143783 ranges between 412 and 854 g . indeed , differences in body weight estimations have important repercussions on eq estimates (
considers that the use of m1 area overestimates the body mass of basal ungulates because they have larger teeth for their body size than do the average modern ones . this assumption gives more credit to the body weight estimate based on the m1 length ( 412 g ) . given the morphological divergence between
and extant ungulates , we consider a body weight estimate comprised between 326 g and 412 g , which corresponds to an eq between 0 . 48 and 0 . 41 following the equation of
; eq = 0 . 36 ) based on a heavier body weight estimate . according to the eq estimates calculated by jerison
ev , endocast volume ; ebm , estimated body mass ; eq1 , encephalization quotient using radinsky ' s [ 20 ] equation ; eq2 , encephalization quotient using eisenberg ' s [ 39 ] equation .
is rather simple among archaic ungulates . there is no junction between the posterior and anterior rhinal fissures , the location of the latter being even difficult to determine with precision (
, the ventral extension of the neopallium is weak and it does not reach the level of what is interpreted here as a vascular sinus . it is comparable to that of
is devoid of fissures and has no trace of suprasylvia or a lateral sulcus , it only exhibits a slight inflation of the posterior part of the neopallium . the same morphology is observed in
( amnh 48082 ; gazin , 1965 ) , which shows a more important posterior inflation of the neopallium . this is in contrast with the neopallium of
bears a long lateral sulcus and another small more ventral depression possibly representing the suprasylvia . after verification on the original endocasts ( mnhn cr 956 , cr 700 )
is rather advanced as its antero - posterior extension almost covers half of the total length of the brain .
( mnhn cr 700 ) , modified after russell and sigogneau ( 1965 ) . not to scale . abbreviations : same as
and represents more than 40 % of the total brain length . by the proportions of the different parts of its brain ,
midbrain exposure is as important as in other archaic ungulates , but its structure is more derived . the reduction of the cerebrum relative to the total length of the endocast in
is most probably correlated with the development of the inferior colliculi . it is noticeable that the morphology of the vermis itself , with a posterior location of the fissure prima , is primitive
presents one of the highest eqs among archaic ungulates , a statement congruent with the derived general proportions of its brain .
presents an “advanced version” of the basal ungulate brain pattern , with a mosaic of archaic ( large olfactory bulbs , weak ventral expansion of the neopallium , absence of neopallium fissuration ) and highly derived ( relative reduction of the cerebellum compared to cerebrum ; enlargement of the inferior colliculus ) characters .
mammalian echolocation is mostly associated with cetaceans in aquatic environments and bats in aerial environments ( e . g . , microchiroptera and megachiroptera ;
. although discussed , the ecological significance of echolocation in shrews was proposed to aid the search for protective cover or for detecting obstacles in subterranean tunnels . evidence for echolocation by means of tongue clicks has also been observed in three tenrecidae both under experimental and natural conditions , and correlated to nocturnal exploration of new environments
. those two insectivorous mammals , although phylogenetically distant ( e . g . ,
) present a rather simple brain structure . however , like in bats , both show a well developed inferior colliculus ; the latter being largely exposed in the tenrecidae
among edentate placentals , the xenarthra chlamyphorus ( pink fairy armadillo , or “ pichiciego ” which means “short - sighted” ) has a subterranean life . it shows a huge enlargement of the posterior ( inferior ) colliculus [ 43 ] compared to the optic midbrain colliculi . edinger [ 43 ] parallels the peculiar morphology of the brain of chlamyphorus and its highly derived forelimbs , specialized for digging . moreover , she relates the large size of the posterior ( inferior ) colliculus to the unique faculty of chlamyphorus among armadillos to have a “voice” [ 63 ] , [ 64 ] . the fact that this mammal is fossorial suggests that the latter , as shrews and tenrecs , might be another example of underground echolocation in extant terrestrial mammals .
digital reconstruction of amnh 143783 left dentition . a , upper and lower cheek teeth in occlusion , lateral view ; b–d , c - m3 in ( b ) occlusal , ( c ) lingual , ( d ) labial views ; e–f , c - m3 in ( e ) occlusal , and ( f ) lingual views . scale bar = 5 mm .
we are particularly grateful to r . o ' leary for her help and access to the amnh collections . many thanks to j . thostenson and m . hill for access to ct scan facilities and acquisition of the ct scan raw data . this is ise - m publication 2011–151 . this work has been possible thanks to the high resolution ct - scanner facility of the amnh funded by the nsf mr1–r2 0959384 granted to n . landman , co - pis : d . ebel , d . frost .
funding : this work has been conducted with the support of the anr ( erc programme palasiafrica ( anr - 08 - jcjc - 0017 - 01 ) . the funders had no role in study design , data collection and analysis , decision to publish , or preparation of the manuscript .
catania kc . cortical organization in insectivora : the parallel evolution of the sensory periphery and the brain .
austin : univ . of texas press , cd - rom , ed . 2 ; 1995 .
rowe tb , macrini te , luo zx . fossil evidence on origin of the mammalian brain .
larsson hce , sereno pc , wilson ja . forebrain enlargement among nonavian theropod dinosaurs .
witmer lm , chatterjee s , franzosa j , rowe t . neuroanatomy of flying reptiles and implications for flight , posture and behavior .
( chondrichthyes , elasmobranchii ) , with observations on the braincase in early chondrichthyans .
marino l , uhen md , frohlich b , aldag jm , blane c , et al . endocranial volume of mid - late eocene archaeocetes ( order : cetacea ) revealed by computed tomography : implications for cetacean brain evolution .
marino l , uhen md , pyenson nd , frohlich b . reconstructing cetacean brain evolution using computed tomography .
macrini te , muizon c , cifelli rl , rowe t . digital cranial endocast of
dechaseaux c . moulages endocrâniens d ' artiodactyles primitifs , essai sur l ' histoire du néopallium .
jerison hj . how can fossils tell us about the evolution of the neocortex . in : kaas jh , editor .
radinsky lb . a new approach to mammalian cranial analysis , illustrated by examples of prosimian primates .
prothero dr , manning em , fischer m . the phylogeny of the ungulates . in : benton mj , editor .
archibald jd . archaic ungulates ( “condylarthra” ) . in : janis cm , scott km , jacobs ll , editors .
evolution of tertiary mammals of north america . volume 1 : terrestrial carnivores , ungulates , and ungulatelike mammals .
rose kd . the beginning of the age of mammals . in : rose kd , editor . baltimore : the john hopkins university press ; 2006 . 428
cope ed . the vertebrata of the tertiary formation of the west . 1884 . rept us geol surv terr , iii .
( mammalia , “condylarthra” ) from the late paleocene of berru ( france ) and phylogenetic affinities of the enigmatic european family pleuraspidotheriidae .
rose kd . clarkforkian land - mammal age : revised definition , zonation , and tentative intercontinental correlations .
janis cm , archibald dj , cifelli rl , lucas sg , schaff cr , et al . part iii : archaic ungulates and ungulatelike mammals . in : janis cm , editor .
damuth j . problems in estimating body masses of archaic ungulates using dental measurements in body size in mammalian paleobiology . in : damuth j , macfadden bj , editors .
legendre s . les communautés de mammifères du paléogène ( eocène supérieur et oligocène ) d ' europe occidentale : structure , milieux et évolution .
malmierca ms , merchán m , henkel ck , oliver dl . direct projections from cochlear nucleus complex to auditory thalamus in the rat .
casseday jh , fremouw t , covey e . the inferior colliculus : a hub for the central auditory system . in : oertel d , popper an , fay rr , editors .
( mammalia , proprimates ) : surface morphology and encephalization compared to those of primates and dermoptera .
malmierca ms . the inferior colliculus : a center for convergence of ascending and descending auditory information .
barton ra , purvis a , harvey ph . evolutionary radiation of visual and olfactory brain systems in primates , bats and insectivores .
gould e , negus n , krech d . evidence for echolocation in shrews .
douady cj , douzery ej . molecular estimation of eulipotyphlan divergence timesand the evolution of “insectivora” .
symonds mre . phylogeny and life histories of the ‘insectivora’ : controversies and consequences .
( mammalia , “condylarthra” ) from the paleocene - eocene of western north america .
rose kd . postcranial skeleton of eocene leptictidae ( mammalia ) , and its implications for behavior and relationships .
( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming .
( merocoidodontidae , oreodontoidea ) and implications for apomorphy based diagnosis of isolated , natural endocasts .
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full reference : j . g . eaton . 1982 . contributions to geology , university of wyoming 21 ( 2 )
average measurements ( in mm ) : m1 3 . 80 x 2 . 82
average measurements ( in mm ) : m1 4 . 90 x 5 . 70 , m2 4 . 80 x 6 . 40 , m3 3 . 60 x 5 . 20 , m1 4 . 90 x 3 . 60
average measurements ( in mm ) : m1 5 . 07 x 6 . 47 , m2 5 . 07 x 7 . 33 , m3 4 . 03 x 6 . 32 , m2 5 . 50 x 4 . 30
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copyright : © 2012 orliac et al . this is an open - access article distributed under the terms of the creative commons attribution license , which permits unrestricted use , distribution , and reproduction in any medium , provided the original author and source are credited .
the superior petrosal sinus is located underneath the cerebellar hemispheres , a continuation of the transverse or lateral sinus system . the posterior part of the sinus system cannot be described because most of the occipital surface of the skull is eroded and the bone is not preserved . the anterior part of the lateral sinus system , or temporal sinus , is partially reconstructed in blue on figure 3 . it extends ventrally and leads to the postglenoid foramen ( path for the external jugular vein ) . dorsally , it leads to several small foramina indicating vascular communication with the temporal surface . posteriorly , the occipital sinus runs external to the petrosal bone and opens on the occipital surface at the level of the mastoid foramen ( path for the mastoid vein ) . ventrally , the petrosal sinus curves slightly forward to the foramen lacerum posterius ( internal jugular vein ) . just ventral to this flexure , and before the sinus reaches the foramen lacerum posterius , a small posterior sinus corresponding to the condyloid canal opens in the internal aspect of the occipital condyle . posteroventral to it , on the side of the medulla oblongata , lies the condylar foramen ( or hypoglossal foramen ) which corresponds to the path of the nerve xii .
ventromedial to the paraflocullus there is the prominence representing the internal auditory meatus with the cast of the facial nerve ( vii ) , and of the auditory nerve ( viii ) located more posteroventrally . the elongated foramen lacerum medium , medial to the internal auditory meatus , connects posteriorly the foramen lacerum posterius by a discrete inferior petrosal sinus . the foramen ovale lies posterolateral to the cavernous sinus and contains the third branch of the trigeminal nerve ( v 3 ) . the surface of the hypophysis or pituitary body cannot be delimited with precision due to deformation and partial preservation of the bone ; however , it might be present on the right side of the specimen , medial to the foramen ovale ( figure 3e ) . the two cavernous sinuses are prominent like in the specimen described by gazin [ 35 ] . they terminate at the position of the posterior aperture to the sphenoidale fissure , and , as suggested by gazin [ 35 ] , comprise a complex of vascular structures and cranial nerves ( iii to vi except v 3 ) .
allman jm ( 1999 ) evolving brains . new york : w . h . freeman and company . 98 p .
catania kc ( 2000 ) cortical organization in insectivora : the parallel evolution of the sensory periphery and the brain . brain behav evol 55 ( 6 ) : 311–321 .
catania kc ( 2005 ) evolution of sensory specializations in insectivores . the anat rec a 287a : 1038–1050 .
catania kc , henry ec ( 2006 ) touching on somatosensory specializations in mammals . curr opin neurobiol 16 : 467–473 .
: digital atlas of the skull . austin : univ . of texas press , cd - rom , ed . 2 .
rowe tb , macrini te , luo zx ( 2011 ) fossil evidence on origin of the mammalian brain . science 332 : 955–957 .
larsson hce , sereno pc , wilson ja ( 2000 ) forebrain enlargement among nonavian theropod dinosaurs . j vertebr paleontol 30 : 615–618 .
witmer lm , chatterjee s , franzosa j , rowe t ( 2003 ) neuroanatomy of flying reptiles and implications for flight , posture and behavior . nature 425 : 950–953 .
( chondrichthyes , elasmobranchii ) , with observations on the braincase in early chondrichthyans . bull am mus nat hist 288 : 1–103 .
marino l , uhen md , frohlich b , aldag jm , blane c , et al . ( 2000 ) endocranial volume of mid - late eocene archaeocetes ( order : cetacea ) revealed by computed tomography : implications for cetacean brain evolution . j mammal evol 7 ( 2 ) : 81–94 .
marino l , uhen md , pyenson nd , frohlich b ( 2003 ) reconstructing cetacean brain evolution using computed tomography . anat rec 272b : 107–117 .
dechaseaux c ( 1969 ) moulages endocrâniens d ' artiodactyles primitifs , essai sur l ' histoire du néopallium . annls paleont ( vert ) 55 ( 2 ) : 195–248 .
jerison hj ( 1973 ) evolution of brain and intelligence . new york : academic press . 482 p .
edinger t ( 1975 ) paleoneurology 1804–1966 . an annotated bibliography . adv anat embryol cell biol 49 : 1–258 .
radinsky lb ( 1977 ) brains of early carnivores . paleobiology 3 : 333–349 .
radinsky lb ( 1978 ) evolution of brain size in carnivorous and ungulates . am nat 112 ( 987 ) : 815–831 .
edinger t ( 1948 ) evolution of the horse brain . geol soc am mem 25 : 1–177 .
jerison hj ( 2009 ) how can fossils tell us about the evolution of the neocortex . in : kaas jh , editor . evolutionary neuroscience . amsterdam : elsevier . pp . 497–508 .
radinsky lb ( 1968 ) a new approach to mammalian cranial analysis , illustrated by examples of prosimian primates . j morphol 124 : 167–180 .
radinsky lb ( 1973 ) evolution of the canid brain . brain behav evol 7 ( 3 ) : 169–202 .
, a middle eocene mesonychid condylarth . fieldiana geol 33 ( 18 ) : 323–337 .
van valen l ( 1978 ) the beginning of the age of mammals . evol theory 4 : 45–80 .
prothero dr , manning em , fischer m ( 1988 ) the phylogeny of the ungulates . in : benton mj , editor . the phylogeny and classification of the tetrapods , volume 2 : mammals . oxford : clarendon press . pp . 201–234 .
archibald jd ( 1998 ) archaic ungulates ( “condylarthra” ) . in : janis cm , scott km , jacobs ll , editors . evolution of tertiary mammals of north america . volume 1 : terrestrial carnivores , ungulates , and ungulatelike mammals . cambridge : cambridge university press . pp . 292–331 .
rose kd ( 2006 ) the beginning of the age of mammals . in : rose kd , editor . baltimore : the john hopkins university press . 428 p .
edinger t ( 1929 ) die fossilen gehirne . zeits gesam anat abtiii 28 : 1–249 .
russell de , sigogneau d ( 1965 ) etude de moulages endocrâniens de mammifères paléocènes . mem mus natl hist nat c 16 ( 1 ) : 1–34 .
cope ed ( 1884 ) the vertebrata of the tertiary formation of the west . rept us geol surv terr , iii .
tilney f ( 1933 ) fossil brains of some early tertiary mammals of north america . bull neurol inst new york 1 : 430–505 .
( mammalia , “condylarthra” ) from the late paleocene of berru ( france ) and phylogenetic affinities of the enigmatic european family pleuraspidotheriidae . j vertebr paleontol 30 ( 5 ) : 1559–1578 .
rose kd ( 1980 ) clarkforkian land - mammal age : revised definition , zonation , and tentative intercontinental correlations . science 208 : 744–746 .
janis cm , archibald dj , cifelli rl , lucas sg , schaff cr , et al . ( 1998 ) part iii : archaic ungulates and ungulatelike mammals . in : janis cm , editor . evolution of tertiary mammals of north america . cambridge : cambridge university press . pp . 247–259 .
eisenberg jf ( 1981 ) the mammalian radiations . chicago : university of chicago press . 610 p .
damuth j ( 1990 ) problems in estimating body masses of archaic ungulates using dental measurements in body size in mammalian paleobiology . in : damuth j , macfadden bj , editors . estimation and biological implications . cambridge : cambridge university press . pp . 229–253 .
legendre s ( 1989 ) les communautés de mammifères du paléogène ( eocène supérieur et oligocène ) d ' europe occidentale : structure , milieux et évolution . müncher geowiss abha 16 : 1–110 .
radinsky lb ( 1976b ) oldest horse brains : more advanced than previously realized . science 194 : 626–627 .
edinger t ( 1964 ) midbrain exposure and overlap in mammals . amer zool 4 : 5–19 . 43 .
butler ab , hodos w ( 1996 ) comparative vertebrate neuroanatomy . evolution and adaptation . new york : wiley - liss . 514 p .
malmierca ms , merchán m , henkel ck , oliver dl ( 2002 ) direct projections from cochlear nucleus complex to auditory thalamus in the rat . j neurosci 22 : 10891–10897 .
casseday jh , fremouw t , covey e ( 2002 ) the inferior colliculus : a hub for the central auditory system . in : oertel d , popper an , fay rr , editors . springer handbook of auditory research . new york : springer . pp . 238–318 .
starck d ( 1963 ) “freiliegendes tectum mesencephali” ein kennzeichen des primitiven säugetiergehirns ? zool anz 171 : 350–359 .
( mammalia , proprimates ) : surface morphology and encephalization compared to those of primates and dermoptera . contrib mus paleontol univ mich 31 ( 8 ) : 185–195 .
malmierca ms ( 2004 ) the inferior colliculus : a center for convergence of ascending and descending auditory information . neuroembryol aging 3 : 215–229 .
barton ra , purvis a , harvey ph ( 1995 ) evolutionary radiation of visual and olfactory brain systems in primates , bats and insectivores . phil trans r soc lond b 348 : 381–392 .
jones g , teeling ec ( 2006 ) the evolution of echolocation in bats . trends ecol evol 21 ( 3 ) : 149–156 .
teeling ec ( 2009 ) hear , hear : the convergent evolution of echolocation in bats ? trends ecol evol 24 ( 7 ) : 351–354 .
gould e ( 1965 ) evidence for echolocation in the tenrecidae of madagascar . proc amer phil soc 109 : 352–360 .
gould e , negus n , krech d ( 1964 ) evidence for echolocation in shrews . j exp zool 156 : 19–38 .
douady cj , douzery ej ( 2003 ) molecular estimation of eulipotyphlan divergence timesand the evolution of “insectivora” . mol phyl evol 28 : 285–296 .
symonds mre ( 2005 ) phylogeny and life histories of the ‘insectivora’ : controversies and consequences . biol rev 80 : 93–128 .
stephan h , baron g , frahm hd ( 1991 ) comparative brain research in mammals volume 1 . insectivora . new york : springer verlag . 573 p .
milne - edwards and grandidier 1872 ( tenrecidae , insectivora ) . j hirnforsch 27 ( 4 ) : 391–399 .
jakobs c ( 1943 ) el pichiciego . un capitolo biogeográphico misterioso de la argentina . rev geogr am 19 : 307–314 .
matthews ( 1928 ) the evolution of the mammals in the eocene . proc zool soc london 1927 : 947–985 .
( mammalia , “condylarthra” ) from the paleocene - eocene of western north america . new mexico mus nat hist sci bull 1 : 1–87 .
rose kd ( 1999 ) postcranial skeleton of eocene leptictidae ( mammalia ) , and its implications for behavior and relationships . j vertebr paleontol 19 : 355–372 .
( mammalia ) from the tepee trail formation ( eocene ) , northwestern wyoming . amer mus nov 3007 : 1–19 .
( merocoidodontidae , oreodontoidea ) and implications for apomorphy based diagnosis of isolated , natural endocasts . j vert paleont 29 ( 4 ) : 1199–1211 .
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an odd - toed ungulate , despite having a five - clawed manus and a four - clawed pes . wikipedia also promotes this nesting , but unlike most ungulates , they report ,
over to the condylarthra adds nearly 30 steps . those tiny feet beneath that long and wide body do not look to me like they could be used to excavate burrows or climb trees . plus that short tail and long torso are not typical of climbing animals .
figure 3 . canis lupus , the wolf that gave rise to extant dogs through selective breeding . note the five phalanges on the manus and four on the pes .
( mammalia , “condylarthra” ) : a case of paleogene terrestrial echolocation ? plosone v . 7 ( 2 ) ; 2012pmc3277592
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the long-tailed forest shrew ( myosorex longicaudatus ) is a species of mammal in the family soricidae endemic to south africa .

its natural habitats are mediterranean-type shrubby vegetation and swamps .

long - tailed forest shrew

wikipedia article copyright notice : this article is licensed under the gnu free documentation license . it uses material from the wikipedia article
long - tailed forest shrew
.
glenn , c . r . 2006 .
earth ' s endangered creatures - long - tailed forest shrew facts
( online ) - licensed article from wikipedia : the free encyclopedia . accessed
facts summary : the long - tailed forest shrew ( myosorex longicaudatus ) is a species of concern belonging in the species group
mammals
and found in the following area ( s ) : south africa .
the forest shrew is a mottled , medium - sized shrew . colouration is grey - brown to dark grey - brown . head and body length is about 83 mm , with a relative short tail of about 45 mm . weighs on average 12 grams . first described to science in 1832 from port elizabeth .
the forest shrew is an opportunistic feeder , taking a great variety of invertebrates like beetles , grasshoppers , termites , moths , spiders , millipedes and earthworms . in turn , it is preyed upon by the barn owl , water mongoose , african weasel and the striped polecat .
all forests in south africa are protected by law , although the degree to which they are protected may vary . this species is also present in protected areas such as the diepwalle forest reserve and tzutzu kama coastal park .
this species is relatively common in suitable habitat . the highest numbers of individuals are found at the forest edge ( dippenaar , 1995 ) . population numbers seems to fluctuate and there is an example of a survey finding no specimens in an area where a previous survey had caught quite high numbers .
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thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
gland , switzerland , 5 july 2018 ( iucn ) – australia’s unique reptiles – including lizards and snakes – face severe threats from invasive species and climate change , with 7 % of th . . .
the value of medicinal and aromatic plant trade has increased three - fold in the past 20 years , but traditional harvesting practices are being replaced by less sustainable alternatives . . . .
a recently released iucn technical brief recommends increasing investments in sustainable land management practices , as well as better cooperation between agriculturalists and conservationists to conse . . .
amori , g . ( small nonvolant mammal red list authority ) & cox , n . ( global mammal assessment team )
justification : listed as vulnerable because its area of occupancy is less than 2 , 000 km² , its distribution is severely fragmented , and there is continuing decline projected in the extent and quality of its habitat .
myosorex longicaudatus is known from the southeastern parts of the cape province , south africa . this species was only discovered in 1978 . this species generally occurs at elevations up to 2 , 000 m asl . a population of the subspecies myosorex longicaudatus boosmai from the langeberg mountains , occurs at much higher elevations ( up to 3 , 600 m asl ) than any other known populations ( dippenaar 1995 ) .
m . longicaudatus is found in forests , forests edges , fynbos and boggy grassland . this species needs a moist microhabitat . it is restricted to pristine primary habitat that has not been degraded .
climate change is considered to be the principal threat to this species . habitat in neighbouring areas is arid and unsuitable for this species which depends on a moist habitat . because of this m . longicaudatus would not be able to move to other areas if the climate in its current range became unsuitable . it is thought that coastal populations might be at less risk than non - coastal populations . the moist habitat of this species is fragmented .
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at higher altitudes the breeding season may be delayed for a month , due to lower ambient temperatures . at normal altitudes the breeding season lasts for seven months , starting in september and ending in march . litter sizes vary between two and five young . these shrews have an advanced maternal care behavioural pattern . nipple - clinging is practiced by the young for the first five to six days . this behaviour is replaced firstly by clustering of young , and then to the formation of a chain , called ' caravanning ' . caravanning entails each offspring gripping the the tail of the preceding sibling in its mouth , thus following the foraging mother like a caravan . weaning takes place between 20 - 25 days after birth .
predominantly nocturnal , showing a sharp rise in activity at dusk and sharp decline at dawn . extremely cautious when leaving the shelter . like most shrews , it is remarkably aggressive . the insides of its burrows and nests are spherical . nests are constructed from grass , and equipped with two to four entrances .
endemic to the eastern regions of south africa and lesotho . found in a variety of vegetation types , ranging from vegetation associated with permanent water on the highveld , to montane grasslands and primary forests .
is known from the southeastern parts of the cape province , south africa . this species was only discovered in 1978 . this species generally occurs at elevations up to 2 , 000 m asl . a population of the subspecies
from the langeberg mountains , occurs at much higher elevations ( up to 3 , 600 m asl ) than any other known populations ( dippenaar 1995 ) .
kari pihlaviita added the finnish common name
pitkähäntähiistäinen
to
myosorex longicaudatus meester and dippenaar , 1978
.
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for the first time in history , a captive cheetah has successfully given birth to eight healthy cubs . it is said that only around 10 , 000 cheetahs remain in the wild in africa along with 100 or fewer in iran .
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mammal species of the world : a taxonomic and geographic reference , 2nd ed . , 3rd printing
mammal species of the world : a taxonomic and geographic reference , 3rd ed . , vols . 1 & 2
with contributions by bernadette n . graham , adam p . potter , and mariana m . upmeyer
disclaimer : itis taxonomy is based on the latest scientific consensus available , and is provided as a general reference source for interested parties . however , it is not a legal authority for statutory or regulatory purposes . while every effort has been made to provide the most reliable and up - to - date information available , ultimate legal requirements with respect to species are contained in provisions of treaties to which the united states is a party , wildlife statutes , regulations , and any applicable notices that have been published in the federal register . for further information on u . s . legal requirements with respect to protected taxa , please contact the u . s . fish and wildlife service .
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to cite this page : myers , p . , r . espinosa , c . s . parr , t . jones , g . s . hammond , and t . a . dewey . 2018 . the animal diversity web ( online ) . accessed at https : / / animaldiversity . org .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .


the six species in the genus didelphis , commonly known as large american opossums , are members of the order didelphimorphia .

the genus is composed of cat-sized omnivorous species , and are recognized on their prehensile tails and the tendency to " play possum " ( feign dead ) when cornered .

the largest species , the virginia opossum , is the only marsupial to be found in north america north of mexico .

didelphis

click to enlarge this image . ( 167kb ) didelphis virginiana ( virginia opossum ) , appalachian trail click to enlarge this image . ( 309kb ) didelphis virginiana ( virginia opossum ) , midatlantic click to enlarge this image . ( 175kb )
origins of chagas disease : didelphis species are natural hosts of trypanosoma cruzi i and armadillos hosts of trypanosoma cruzi ii , including hybrids .
origins of chagas disease : didelphis species are natural hosts of trypanosoma cruzi i and armadillos hosts of trypanosoma cruzi ii , including hybrids . - pubmed - ncbi
to cite this page : siciliano martina , l . 2014 .
didelphis marsupialis
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
to cite this page : siciliano martina , l . 2013 .
didelphis virginiana
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
shripat , v . 2011 .
the online guide to the animals of trinidad and tobago
( on - line ) . the university of the west indies . accessed may 21 , 2013 at http : / / sta . uwi / fst / lifesciences / documents / didelphis _ marsupialis . pdf .
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i thought you might be interested in this item at urltoken title : mammal species of the world : a taxonomic and geographic reference author : don e wilson ; deeann m reeder publisher : baltimore : johns hopkins university press , ©2005 . isbn / issn : 0801882214 9780801882210 0801882389 9780801882388 0801882397 9780801882395 oclc : 57557352
wilson and reeder ' s mammal species of the world is the classic reference book on the taxonomic classification and distribution of the more than 5400 species of mammals that exist today . the third edition includes detailed information on nomenclature and , for the first time , common names . each concise entry covers type locality , distribution , synonyms , and major reference sources . the systematic arrangement of
information indicates evolutionary relationships at both the ordinal and the family level . this indispensable reference work belongs in public and academic libraries throughout the world and on the shelf of every biologist who works with mammals .
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this indispensable reference work belongs in public and academic libraries throughout the world and on the shelf of every biologist who works with mammals .
a uniquely valuable compendium of taxonomic and distributional data on the world ' s living and historically extinct mammalian species . contributors and editors alike deserve the thanks of all
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wilson and reeder ' s mammal species of the world is the classic reference book on the taxonomic classification and distribution of the more than 5400 species of mammals that exist today . the third edition includes detailed information on nomenclature and , for the first time , common names . each concise entry covers type locality , distribution , synonyms , and major reference sources . the systematic arrangement of information indicates evolutionary relationships at both the ordinal and the family level . this indispensable reference work belongs in public and academic libraries throughout the world and on the shelf of every biologist who works with mammals .
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) are found throughout much of central and south america . the range of this species is limited by high elevations and dry environments . these animals are found native to the following countries : argentina , belize , bolivia , brazil , columbia , costa rica , ecuador , el salvador , french guiana , guatemala , guyana , honduras , mexico , nicaragua , panama , paraguay , peru , suriname , trinidad , tobago and venezuela . in recent history , these animals have also been introduced to a variety of islands .
( brito , et al . , 2008 ; cerqueira and tribe , 2008 )
common opossums are found in a variety of habitats throughout central and south america . these animals are considered habitat generalists and are even tolerant of anthropogenically altered environments . they are not found in areas of exceptionally high elevation or extremely dry habitats , although they are found in montane environments in costa rica and may survive in areas with a wide range of precipitation . it has been suggested that common opossums may be the most tolerant and adaptable neotropical mammal . their preferred habitats include tropical , subtropical , old growth , evergreen and gallery forests in lowland regions below about 2 , 000 meters on average . these animals also frequent urban environments such as near human dwellings and garbage dumps , as well as agricultural lands including pastures and cacao , coffee and citrus plantations . common opossums may be found on the ground or in large trees , although they are more terrestrial than some members of their genus .
( adler , et al . , 2012 ; brito , et al . , 2008 ; cerqueira and tribe , 2008 ; estrada , et al . , 1994 ; medellin , 1994 ; reid , 2009 ; tyndale - biscoe , 1973 )
common opossums are robust marsupials . the fur on their body is thick with long guard hairs , leading these animals to appear somewhat disheveled . their dorsal pelage is often dark , typically blackish or grayish , but in rare instances they may appear whitish . in comparison , their ventral fur is yellow or cream . these animals have primarily whitish fur on their faces and a dark stripe extending to the crown of their heads , with a black ring around both eyes . their ears are large and all black . common opossums have sharp claws , long whiskers and a primarily naked prehensile tail that is slightly longer than their body . these animals are sexually dimorphic ; males trapped in french guiana averaged 1 . 2 kg , whereas females averaged 1 . 03 kg . these values may be low ; other sources suggest that their body weights range between 4 to 6 kg . in general , adult males have longer canines than adult females . common opossums typically have a total body length of 371 mm ( ranging from 265 to 430 mm ) , including a tail length of 395 mm .
( castillo - flores and calvo - irabien , 2003 ; reid , 2009 ; richard - hansen , et al . , 1999 ; shripat , 2011 ; tyndale - biscoe and renfree , 1987 )
common opossums show a polygynous mating system , in which males compete for reproductive females . these animals are almost exclusively solitary , but come together seasonally for breeding .
do not exhibit courtship rituals and do not pair bond . females experience a 25 to 32 day estrous cycle . when resources are limited or unavailable these animals may choose not to mate .
( fernandes , et al . , 2010 ; julien - laferriere and atramentowicz , 1990 ; o ' connell , 2006 ; shripat , 2011 ; sunquist , et al . , 1987 )
breeding seasons and the number of annual litters varies based on latitude . breeding seasons can vary from one long season from january to september or several shorter seasons annually . these seasons may be correlated with seasonal precipitation . female common opossums begin breeding when they are 6 to 7 months old . gestation typically lasts 13 to 15 days , after which 2 to 20 altricial young are born , interestingly ; animals living closer to the equator tend to have smaller litters . at birth , their young are tiny ; they are usually about 1 cm long and weigh about 0 . 13 grams . although they are extremely under - developed , newborn common opossums have well - developed claws on their front legs that help them climb to their mother’s pouch . once inside the pouch , their young remain attached to the mammae for about 50 days . young are weaned and independent when they are 90 to 125 days old , often when fruit is plentiful .
( brito , et al . , 2008 ; cabello , 2006 ; gustavo , et al . , 1990 ; julien - laferriere and atramentowicz , 1990 ; o ' connell , 2006 ; shripat , 2011 ; tyndale - biscoe and mackenzie , 1976 ; tyndale - biscoe and renfree , 1987 ; tyndale - biscoe , 1973 ; tyndale - biscoe , 2005 )
breeding season breeding season varies depending on latitude , but likely correlates to seasonal precipitation .
common opossums offer very little parental care . males have no involvement in raising their offspring and females invest a minimal effort . when their tiny offspring are born , they begin a harrowing journey to their mother’s pouch ; many of the young will not survive . female common opossums typically only have 9 teats available for nursing , so they often have more offspring than they can accommodate . however , they have a fairly low mortality rate once they are safely inside the pouch and nursing . the young may begin leaving the pouch when they are about 70 days old , at which time they may begin riding on their mother’s back while she forages . the young become independent when they are weaned between 90 and 125 days old . interestingly , a study in venezuela determined that females with ample resources are more likely to have mostly male offspring , whereas , when resources become limited they typically have a greater number of females in their litters .
common opossums are very short lived ; they typically live fewer than 2 years . in a long term study of these animals , the oldest individual lived to be 20 months old , in another study ; the oldest individual lived to be 11 months old . these animals experience their greatest mortality rate prior to maturity and while lactating . common opossums are frequent victims of collisions with cars .
( kajin , et al . , 2008 ; pinowski , 2005 ; reid , 2009 ; sunquist , et al . , 1987 )
common opossums are solitary and nocturnal . they begin their daily activities about an hour before sunset ; however , their activity level peaks from 11 pm to 3 am . these animals are primarily terrestrial but spend a significant amount of time in trees , although other members of their genus are much more arboreal . during daylight hours , common opossums stay inside their burrows . burrow locations vary and include tree cavities , underground , in palm or fig trees , in the tree canopy or in the abandoned nests of other species . these animals do not maintain a burrow for very long , males remain in the same den for about 1 . 5 days on average and females remain in the same den for about 5 . 1 days .
( adler , et al . , 2012 ; brito , et al . , 2008 ; julien - laferriere and atramentowicz , 1990 ; reid , 2009 ; shripat , 2011 ; sunquist , et al . , 1987 ; vaughan , et al . , 1999 )
male common opossums maintain a much larger home range than their female counterparts . females average 16 . 3 hectares ( + / - 8 . 2 ha ) , whereas males average a home range of 123 hectares ( + / - 60 . 8 ha ) . male home ranges overlap ; generally there is about one individual per hectare .
( brito , et al . , 2008 ; sunquist , et al . , 1987 )
common opossums use a variety of perception channels . their auditory ability develops relatively late in life , young do not fully develop their auditory capabilities until they are about 80 days old . common opossums may communicate vocally , specifically when they are engaged in an aggressive encounter . in such circumstances , these animals may hiss , growl or screech . common opossums also perform a variety of visual displays when engaged in an aggressive interaction including rocking from side to side , drooling , baring their teeth , and in the case of an extreme threat , these animal have also been known to enter a catatonic state , commonly known as ‘playing opossum’ . olfaction is also used to communicate ; common opossums may produce a secretion from their anal gland or spray urine and feces when a threat is perceived . their vision is acute and is likely on par with the visual abilities of cats ; however , their visual acuity is limited when compared to some primates .
( ehret , 1983 ; oswaldo - cruz , et al . , 1979 ; reid , 2009 ; shripat , 2011 ; volchan , et al . , 2004 )
common opossums have a very broad diet . their feeding habits are often referred to as opportunistic omnivory . their diet includes invertebrates , vertebrates , leaves , fruits , nectar and carrion . common opossums may alter their diet seasonally , during the dry season mammals and birds are more likely consumed , whereas during the wet season they rely more heavily on fruits , snakes and toads . regardless of the season , invertebrates are a primary staple of their diet including
. after weaning , their diet remains fairly constant throughout their life , although older animals tend to consume vertebrates more frequently . common opossums eat a variety of vertebrates including birds such as
and a variety of small mammals . interestingly , their ability to consume rattlesnakes is facilitated by their apparent immunity to the venom of many members of family
( almeida - santos , et al . , 2000 ; cerqueira and tribe , 2008 ; cordero and nicolas , 1987 ; garrett and boyer , 1993 ; reid , 2009 ; reidy , 2009 )
given their abundance , common opossums are likely prey for a variety of large mammals throughout central and south america . their known predators include
. when a threat is detected , common opossums may choose to run or climb a tree to evade predators . less frequently , these animals may enter a catatonic state , commonly known as ' playing opossum ' . this death feigning behavior may last as little as 1 minute or as long as 6 hours .
( gustavo , et al . , 1990 ; rotenberg , et al . , 2012 ; shripat , 2011 )
common opossums carry a variety of parasites ; some reports claim they may carry up to 46 species of internal and external parasites . most notably ,
in their large and small intestines . common opossums are also important seed dispersers . they move some seeds due to ingestion after eating fruits , such as for
. these plants are anthropogenic herbs and have been introduced to the forest understory partially via the fur of animals .
( castillo - flores and calvo - irabien , 2003 ; cerqueira and tribe , 2008 ; deane , et al . , 1984 ; jimenez , et al . , 2011 ; medellin , 1994 )
common opossums are often hunted by humans . they are killed for sport and food and are even part of the illegal wild game trade . some cultures believe that the fat of common opossums can be used to treat a variety of ailments including stomach aches , rheumatism , diarrhea , inflammation , skin infections , labor pains , asthma , headaches , toothaches , ear aches and sore throats .
( alves and rosa , 2006 ; alves and rosa , 2007 ; brito , et al . , 2008 ; junior , et al . , 2010 )
common opossums are known to transmit diseases which impact human populations , such as chagas disease and leishmaniansis . these animals may also be considered pests due to their aptitude for killing bats caught in research mist nets and their proclivity for poultry .
( brito , et al . , 2008 ; cabello , 2006 ; deane , et al . , 1984 ; reid , 2009 )
common opossums are currently listed as a species of least concern according to the iucn red list of threatened species . these animals are found throughout much of central and south america and likely have a very large population size . their ability to live in anthropogenically disturbed environments facilities this species broad success .
are commonly grouped into either ‘white - eared’ or ‘black - eared opossums’ . common opossums (
living in the southern part of the new world . in other words , central and south america .
young are born in a relatively underdeveloped state ; they are unable to feed or care for themselves or locomote independently for a period of time after birth / hatching . in birds , naked and helpless after hatching .
having body symmetry such that the animal can be divided in one plane into two mirror - image halves . animals with bilateral symmetry have dorsal and ventral sides , as well as anterior and posterior ends . synapomorphy of the bilateria .
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature . endothermy is a synapomorphy of the mammalia , although it may have arisen in a ( now extinct ) synapsid ancestor ; the fossil record does not distinguish these possibilities . convergent in birds .
forest biomes are dominated by trees , otherwise forest biomes can vary widely in amount of precipitation and seasonality .
offspring are produced in more than one group ( litters , clutches , etc . ) and across multiple seasons ( or other periods hospitable to reproduction ) . iteroparous animals must , by definition , survive over multiple seasons ( or periodic condition changes ) .
this terrestrial biome includes summits of high mountains , either without vegetation or covered by low , tundra - like vegetation .
the area in which the animal is naturally found , the region in which it is endemic .
rainforests , both temperate and tropical , are dominated by trees often forming a closed canopy with little light reaching the ground . epiphytes and climbing plants are also abundant . precipitation is typically not limiting , but may be somewhat seasonal .
the region of the earth that surrounds the equator , from 23 . 5 degrees north to 23 . 5 degrees south .
living in cities and large towns , landscapes dominated by human structures and activity .
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female .
adler , g . , a . carvajal , s . davis - foust , j . dittel . 2012 . habitat associations of opossums and rodents in a lowland forest in french guiana .
almeida - santos , s . , m . antoniazzi , o . sant ' anna , c . jared . 2000 . predation by the opossum
alves , r . , i . rosa . 2006 . from cnidarians to mammals : the use of animals as remedies in fishing communities in northeast brazil .
alves , r . , i . rosa . 2007 . zootherapeutic practices among fishing communities in north and northeast brazil . a comparison .
austad , s . , m . sunquist . 1987 . sex ratio manipulation in the common opossum .
brito , d . , d . astuade moraes , d . lew , p . soriano , l . emmons , a . cuaron , k . helgen , r . reid , e . vazquez . 2008 .
( on - line ) . iucn red list of threatened species . accessed may 21 , 2013 at
castillo - flores , a . , l . calvo - irabien . 2003 . animal dispersal of two secondary - vegetation herbs into the evergreen rainforest of south - eastern mexico .
ehret , g . 1983 . development of hearing and response behavior to sound stimuli : behavioral studies . pp . 211 - 237 in r romand , ed .
estrada , a . , r . coates - estrada , d . merritt jr . 1994 . non - flying mammals and landscape change in the tropical rainforest region of los tuxtlas , mexico .
gustavo , a . , b . da fonseca , j . robinson . 1990 . forest size and structure : competitive and predatory effects on small mammal communities .
julien - laferriere , d . , m . atramentowicz . 1990 . feeding and reproduction of three
junior , p . , d . guimaraes , y . le perdu . 2010 . non - legalized commerce in game meat in the brazilian amazon : a case study .
o ' connell , m . 2006 . american opossums . pp . 808 - 813 in d macdonald , s norris , eds .
oswaldo - cruz , e . , j . hokoc , a . sousa . 1979 . a schematic eye for the opossum .
reidy , j . 2009 . nest predators of lance - tailed manakins on isla boca brava , panama .
richard - hansen , c . , j . vie , n . vidal , j . keravec . 1999 . body measurements on 40 species of mammals from french guiana .
tyndale - biscoe , c . , r . mackenzie . 1976 . reproduction in
volchan , e . , c . vargas , j . da franca , a . pereira jr , c . da rocha - miranda . 2004 . tooled for the task : vision in the opossum .
disclaimer : the animal diversity web is an educational resource written largely by and for college students . adw doesn ' t cover all species in the world , nor does it include all the latest scientific information about organisms we describe . though we edit our accounts for accuracy , we cannot guarantee all information in those accounts . while adw staff and contributors provide references to books and websites that we believe are reputable , we cannot necessarily endorse the contents of references beyond our control .
this material is based upon work supported by the national science foundation grants drl 0089283 , drl 0628151 , due 0633095 , drl 0918590 , and due 1122742 . additional support has come from the marisla foundation , um college of literature , science , and the arts , museum of zoology , and information and technology services .
( cuaron , et al . , 2012 ; harmon , et al . , 2005 ; hossler , et al . , 1994 ; kanda , 2005 )
virginia opossums may be found in a fairly wide range of habitats ; however , they typically prefer areas near a water source , such as a stream or swamp . these animals may live in woodlands and thickets but they are very often found within human altered areas . this species has been extremely successful due to their ability to thrive in urban areas ; this is assisted by their small body size , nocturnal habits and high reproductive output . virginia opossums nest in brush piles , hallow trees and drainage areas . they can be found from near sea level to 3 , 000 meters in elevation .
( cuaron , et al . , 2012 ; hoffmeister , 2002 ; mcmanus , 1974 ; wright , et al . , 2012 )
( burnie , et al . , 2001 ; christiansen , 2006 ; gipson and kamler , 2001 ; hoffmeister , 2002 ; hossler , et al . , 1994 ; mcmanus , 1974 ; mcruer and jones , 2009 ; wright , et al . , 2012 )
marsupials engage in a polygynous mating system , in which males vie for reproductive females . male virginia opossums possess a sexually dimorphic scent gland on their chest , which emits a musky odor and stains their fur ; this is most commonly observed near the onset of the breeding season . females experience an approximately 29 . 5 day estrous cycle , upon entering estrous , breeding begins almost immediately . mating behavior is one of the only social behaviors displayed by virginia opossums , after mating ; females resume their aggressive , solitary disposition .
( christiansen , 2006 ; fernandes , et al . , 2010 ; holmes , 1992a ; mcmanus , 1974 )
( burnie , et al . , 2001 ; christiansen , 2006 ; feldhamer , et al . , 2007 ; hoffmeister , 2002 ; holmes , 1992b ; hossler , et al . , 1994 ; mcmanus , 1974 ; o ' connell , 2006 ; rademaker and cerqueira , 2006 )
breeding interval this species has 1 to 3 litters per year ; this varies based on a populations range .
breeding season the exact breeding season for this species varies based on a population’s range , in more northern climates they breed from february to september ; in ranges further south they breed from january to august .
virginia opossums invest little in parental care ; males provide no parental care , while females offer moderate care . after breeding , the female’s pouch takes on a brownish - orange hue and emits a musky odor due to scent glands located within ; this likely assists newborn opossums in finding their mothers pouch . while young are residing within , females are often observed licking at the pouch and their offspring . this practice led to the mistaken idea that virginia opossums breed with their noses and afterward , the young crawl from the female’s nostrils into her pouch . although a female with pouch - young may become very protective of her pouch , once her young are removed , females show little interest . female virginia opossums typically continue lactating for about 15 weeks , over which time , the composition of the milk becomes modified . most young virginia opossums become solitary after weaning , however , some may remain with their mother in their weaning den until they are about 120 days old .
virginia opossums have a fairly short lifespan ; wild individuals typically only survive about 1 . 5 to 2 years . early in life , young opossums have a very high mortality rate . many of these altricial young never arrive in their mothers pouch , afterward ; about 60 % of those who do reach the pouch will perish once they are weaned . among adult animals , the vast majority of deaths occurred during the cold season . although males typically only participate in breeding for one year , they are technically not semelparous because most ranges involve 2 to 3 breeding seasons per year . however , in one study , among approximately 12 , 000 trapped virginia opossums , no adult males were found . females may live slightly longer than their male counterparts ; however , they are no longer reproductively viable after 2 years of age . captive individuals typically have a longer lifespan ; they generally survive to be 3 to 4 years old ; however , there are reports of captive virginia opossums surviving until they are 8 to 10 years old .
( christiansen , 2006 ; gipson and kamler , 2001 ; harmon , et al . , 2005 ; hossler , et al . , 1994 ; mcmanus , 1974 ; mcruer and jones , 2009 ; o ' connell , 2006 ; woods ii and hellgren , 2003 )
( allen , et al . , 1985 ; cuaron , et al . , 2012 ; hoffmeister , 2002 ; hossler , et al . , 1994 ; kimble , 1997 ; ladine and kissell jr , 1994 ; mcmanus , 1974 ; mcruer and jones , 2009 )
the home range kept by virginia opossums varies greatly . this may depend on their range , their habitat , the availability of resources and their gender . in general , their home range size is thought to be about 12 . 5 to 38 . 8 hectares ; females generally have a smaller home range . a study conducted in georgia found that home range size may be between 7 . 2 to 94 . 4 hectares , a study in texas found home range sizes from 0 . 12 to 23 . 47 hectares ; likewise , home range sizes in urban environments averaged 18 . 8 hectares for females and 37 . 3 hectares for males . males are believed to keep larger home ranges because their reproductive success is based solely on their ability to find mates , whereas female success is based on the accessibility of food items . their home ranges are oval shaped and often overlap with a water source . virginia opossums were once considered a nomadic species but more recent research has shown that an individual maintains a fairly constant home range throughout their lifespan .
( allen , et al . , 1985 ; gehrt , et al . , 1997 ; gipson and kamler , 2001 ; harmon , et al . , 2005 ; mcmanus , 1974 ; o ' connell , 2006 ; wright , et al . , 2012 )
virginia opossums are extremely opportunistic feeders . these animals eat a variety of foods based on the season , their habitat and their range . their diets include vertebrates , invertebrates , plant material , fruits , grains and carrion . during the colder seasons , small vertebrates tend to make up a larger portion of their diet , whereas in the warmer seasons , they consume more invertebrates , plant material , fruits and seeds . stomach content analyses have been conducted on virginia opossums throughout the united states , generally their diet is composed of 14 to 27 % mammal tissues , 10 to 18 % fruits , seeds and bulbs , 6 to 11 % grasses and leaves , 3 to 13 . 5 % insects , 5 . 5 to 9 %
and 3 to 5 % birds . other food items were found more specific to an animal’s location and included up to 22 . 5 %
, 9 % pet food , 9 % garbage and up to 5 % carrion .
. this species may have a better chance of survival within more urban environments due partially to the lower predation risk .
( harmon , et al . , 2005 ; hossler , et al . , 1994 ; ladine and kissell jr , 1994 ; werner and vick , 1977 )
virginia opossums are opportunistic omnivorous feeders . they consume a variety of vertebrates , invertebrates , plant material and carrion . virginia opossums are important seed dispersers and redistribute undamaged seeds from the genera
, among others . these animals are also carriers for a wide variety of internal and external parasites . virginia opossums are known carriers of at least 24 internal and 13 external parasites . although they are not immune , it is unusual for this species to be a carrier of the rabies virus .
( baker , et al . , 1995 ; durden and nixon , 1990 ; mcmanus , 1974 ; mcruer and jones , 2009 ; monet - mendoza , et al . , 2005 ; rejmanek , et al . , 2009 ; willson , 1993 )
given the frequent urban habitation of virginia opossums , interaction with humans is almost inevitable . these animals are hunted for sport and food . some cultures believe that virginia opossums’ meat has medical properties . for instance , eating their meat in a soup is believed to help inflammation , colitis , gastritis and skin infections . likewise eating cooked virginia opossum meat is believed to prevent heart attacks , using an ointment composed of opossum fat is believed to treat epilepsy and infusing opossum bones in water is believe to treat allergies , dermatitis and coughing . virginia opossums’ pelts may also be sold commercially . although it is illegal in many states , virginia opossums are sometimes kept as pets . in such situations , these animals may be successfully litter trained and adapt to the diurnal lifestyle of their owners . obesity is common among captive virginia opossums .
( alonso - castro , et al . , 2011 ; cuaron , et al . , 2012 ; jacobo - salcedo , et al . , 2011 ; mcmanus , 1974 ; mcruer and jones , 2009 )
virginia opossums are often seen a pest species . stomach content analyses in portland , oregon found that as much as 9 % of an opossums diet was composed of garbage , likewise , another 9 % of their diet was pet food . virginia opossums are also seen as farm pests due to their proclivity for poultry .
( cuaron , et al . , 2012 ; mcruer and jones , 2009 )
virginia opossums are currently listed as a species of least concern according to the iucn red list of threatened species . this animal’s ability to adapt to human altered habitats has made it extremely successful and widespread . virginia opossums do not merely tolerate human settlements ; they flourish and have a greater survival rate near them .
( cuaron , et al . , 2012 ; harmon , et al . , 2005 ; wright , et al . , 2012 )
living in the nearctic biogeographic province , the northern part of the new world . this includes greenland , the canadian arctic islands , and all of the north american as far south as the highlands of central mexico .
referring to animal species that have been transported to and established populations in regions outside of their natural range , usually through human action .
a wetland area that may be permanently or intermittently covered in water , often dominated by woody vegetation .
that region of the earth between 23 . 5 degrees north and 60 degrees north ( between the tropic of cancer and the arctic circle ) and between 23 . 5 degrees south and 60 degrees south ( between the tropic of capricorn and the antarctic circle ) .
allen , c . , r . marchinton , w . maclentz . 1985 . movement , habitat use and denning of opossums in the georgia piedmont .
alonso - castro , a . , c . carranza - alvarez , j . maldonado - miranda , m . jacobo - salcedo , d . quezada - rivera , h . lorenzo - marquez , l . figueroa - zuniga , c . fernandez - galicia , n . rios - reyes , m . de leon - rubio , v . rodriguez - gallegoes , p . medellin - milan . 2011 . zootherapeutic practices in aquismon , san luis potos , mexico .
( on - line ) . iucn red list of threatened species . accessed may 02 , 2013 at
gehrt , s . , d . clark , e . fritzell . 1997 . population dynamics and ecology of virginia opossums in southern texas .
gipson , p . , j . kamler . 2001 . survival and home ranges of opossums in northeastern kansas .
holmes , d . 1992 . odor as cues for orientation to mothers by weaning virginia opossums .
hopkins , d . , r . forbes . 1980 . dietary patterns of the virginia opossum in an urban environment .
hossler , r . , j . mcaninch , j . harder . 1994 . maternal denning behavior and survival of juveniles in opossums in southeastern new york .
jacobo - salcedo , m . , a . alonso - castro , a . zarate - martinez . 2011 . folk medicinal use of fauna in mapimi , durango , mexico .
ladine , t . , r . kissell jr . 1994 . escape behavior of virginia opossums .
monet - mendoza , a . , d . osorio - sarabia , l . garcia - prieto . 2005 . helminthes of the virginia opossum (
woods ii , h . , e . hellgren . 2003 . seasonal changes in the physiology of male virginia opossums (
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thank you for taking the time to provide feedback on the iucn red list of threatened species website , we are grateful for your input .
justification : a widespread and common species throughout its range , this species is adaptable to human dominated landscapes . although hunted or trapped locally for food , sport and as predators of poultry , apparently the species has not been adversely affected by human settlement , in fact its range appears to be expanding . commercial hunting for the fur trade does not appear to have much impact .
this species is found in central america , from costa rica to mexico and in the united states east of the rocky mountains , and north into southwestern ontario , canada ( the northernmost locality reached by a marsupial ) . some introduced populations are also found along the west coast of the united states and recently into british columbia ( canada ) . their range , limited by winter temperatures and snow depth , appears to be expanding northwards ( gardner 2005 ) . this species can be found from lowlands to 3 , 000 m ( reid 1997 ) .
this species is found in a variety of habitats , ranging from relatively arid to mesic environments . they prefer wet areas , however , especially woodlands and thickets near streams and swamps . also in suburban areas . the opportunistic denning and feeding habits of the virginia opossum has led to the success of the species , especially in areas of habitat fragmentation . high reproductive potential further contributes to increasing population size ( mcmanus 1974 ) . abandoned burrows , buildings , hollow logs , and tree cavities are generally used for den sites .
although opossums were once important in the fur trade , this activity has apparently had little impact on the species ' population ( whitaker jr . and hamilton jr . , 1998 ) .
there are no major threats to this species . opossums are hunted and trapped for food and fur in certain areas of their range , but the mortality is mostly caused by collision with motor vehicles ( gardner 2005 ) .
there are no specific measures in place to protect the virginia opposum , as it likely occurs in a number of protected areas throughout its range .
to make use of this information , please check the < terms of use > .
astua de moraes , d . , lew , d . , costa , l . p . & pérez - hernandez , r .
justification : this species is listed as least concern because of its wide distribution , presumed large population , tolerance to habitat modification , occurrence in a number of protected areas and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category . although hunted or trapped locally for food , sport and as predators of poultry , the species does not appear to have been adversely affected by human settlement . commercial hunting for fur trade does not appear to have much impact .
the species is found from tamaulipas , mexico , and in cozumel and the yucatan peninsula , south to perú , bolivia , paraguay and northeastern argentina , including trinidad and the lesser antilles ( emmons and feer 1997 , eisenberg and redford 1999 , gardner 2008 ) . it can be found to about 2 , 000 m . a . s . l . ( eisenberg and redford 1999 , emmons and feer 1997 ) .
this species is common , and is hunted for meat only where other game is scarce ( emmons and feer 1997 ) . densities of 0 . 25 - 2 . 5 individuals per hectare are found in venezuela ( august 1984 , o ' connell 1979 ) , of 0 . 22 - 0 . 45 in french guiana ( atramentowicz 1986 , charles - dominique et al . 1981 , julien - laferriere 1991 ) and of 0 . 09 - 1 . 32 in panamá ( fleming 1972 ) .
this species is hunted only where other game is scarce ( emmons and feer 1997 ) .
there are no major threats known to this species . in suriname , it is collected for its meat which is illegally exported to french - guiana ( j . de bruin , in litt . ) .
astua de moraes , d . , lew , d . , costa , l . p . & pérez - hernandez , r . 2016 .
astua de moraes , d . , de la sancha , n . & costa , l .
justification : this species is listed as least concern because of its wide distribution , presumed large population , tolerance to habitat modification , occurrence in a number of protected areas and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category . although hunted or trapped locally for food , sport and as predators of poultry , this species does not appear to have been adversely affected by human settlement ( nowak 1999 ) . commercial hunting for the fur trade does not appear to have much impact .
this species occurs in coastal brazil from bahia to rio grande do sul , to east of the lower rio paraguay and northeastern argentina ( gardner 2008 ) .
this species is found in the atlantic and aracaria forests , living in primary and secondary forests . it is also found in forests that have been fragmented by urban development and deforestation ( grelle 2003 ) . it is a habitat generalist ( emmons and feer 1997 ) and often moves long distances ( gentile and cerqueira 1995 ) . the diet of d . aurita is omnivorous ( carvalho et al . 2005 ) . it is scansorial , nocturnal and solitary . it is mainly terrestrial , but its forelimbs and claws allow it to climb trees ( grelle 2003 ) .
this species is locally hunted for food and sport . it is also hunted for the commercial fur trade .
there are no major threats known , although deforestation effects some subpopulations ( e . g . eastern paraguay ) . although hunted or trapped locally for food , sport and as predators of poultry , this species does not appear to have been adversely affected by human settlement ( nowak 1999 ) . commercial hunting for the fur trade does not appear to have much impact .
astua de moraes , d . , de la sancha , n . & costa , l . 2015 .
at home on the ground and in the trees . opossums prefer forested habitats , but they are quite successful even in urban areas . they are active at night , year - round : in freezing weather , an unlucky opossum can lose its ear - tips and the end of its tail to frostbite . like all
, opossums give birth to tiny , undeveloped young . the embryos develop in the mother ' s womb for less than two weeks , then the newborn opossums crawl from the birth canal to the mother ' s pouch , where they fasten tight to a nipple . they stay there , attached to the nipple , for 55 or 60 days . a female opossum usually has 13 nipples , and litters are usually smaller than that , but a baby that cannot attach to a nipple dies . after about 60 days the young opossums leave the pouch , but they stay close to their mother—sometimes riding on her back when they are out at night—and nurse for another month or more .
sexual dimorphism : males are slightly larger and much heavier than females , with larger canine teeth .
kerr , r . , 1792 . the animal kingdom , or zoological system , of the celebrated sir charles linnaeus . class i . mammalia , p . 193 . london , 651 pp .
mammal species of the world ( opens in a new window ) . mammalian species , american society of mammalogists ' species account ( opens in a new window ) .
this page was last edited on 23 february 2018 , at 13 : 36 .
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banks , r . c . , r . w . mcdiarmid , and a . l . gardner
checklist of vertebrates of the united states , the u . s . territories , and canada
walker ' s mammals of the world , vol . 1 , 5th ed .
mammal species of the world : a taxonomic and geographic reference , 2nd ed . , 3rd printing
mammal species of the world : a taxonomic and geographic reference , 3rd ed . , vols . 1 & 2
disclaimer : itis taxonomy is based on the latest scientific consensus available , and is provided as a general reference source for interested parties . however , it is not a legal authority for statutory or regulatory purposes . while every effort has been made to provide the most reliable and up - to - date information available , ultimate legal requirements with respect to species are contained in provisions of treaties to which the united states is a party , wildlife statutes , regulations , and any applicable notices that have been published in the federal register . for further information on u . s . legal requirements with respect to protected taxa , please contact the u . s . fish and wildlife service .
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yeo m 1 , acosta n , llewellyn m , sánchez h , adamson s , miles ga , lópez e , gonzález n , patterson js , gaunt mw , de arias ar , miles ma .
department of infectious and tropical diseases , london school of hygiene and tropical medicine , keppel street , london , uk . matthew . yeo @ urltoken
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