,,university ,,of ,,kansas ,,publications ,,museum ,,of ,,natural ,,history ,volume #ad1 ,no4 #ag1 pp4 #dhc-dia1 #b figs4 ,march #b1 #aifd ,records of the ,fossil ,mammal ,sinclairella1 ,family ,apatemyidae1 ,from the ,chadronian and ,orellan ,,by ,,william ,a4 ,,clemens1 ,,jr4 ,,university ,,of ,,kansas ,,lawrence #aifd ,,university ,,of ,,kansas ,,publications1 ,,museum ,,of ,,natural ,,history ,editors3 ,e4 ,raymond ,hall1 ,chairman1 ,henry ,s4 ,fitch1 ,theodore ,h4 ,eaton1 ,jr4 ,volume #ad1 ,no4 #ag1 pp4 #dhc-dia1 #b figs4 ,published ,march #b1 #aifd ,,university ,,of ,,kansas ,lawrence1 ,kansas ,,printed ,,by ,,harry 7,,bud7 ,,timberlake1 ,,state ,,printer ,,topeka1 ,,kansas #aifd #bi-hehg ,records of the ,fossil ,mammal ,sinclairella1 ,family ,apatemyidae1 ,from the ,chadronian and ,orellan ,,by ,,william ,a4 ,,clemens1 ,,jr4 ,introduction ,the family ,apatemyidae has a long geochronological range in ,north ,america1 beginning in the ,torrejonian land-mammal age1 but is represented by a relatively small number of fossils found at a few localities4 ,two fossils of ,orellan age1 found in northeastern ,colorado and described here1 demonstrate that the geochronological range of the ,apatemyidae extends into the ,middle ,oligocene4 ,isolated teeth of ,sinclairella dakotensis ,jepsen1 part of a sample of a ,chadronian local fauna collected by field parties from the ,webb ,school of ,california1 are also described4 ,i thank ,mr4 ,raymond ,m4 ,alf1 ,webb ,school of ,california1 ,claremont1 ,california1 and ,dr4 ,peter ,robinson1 ,university of ,colorado ,museum1 ,boulder1 ,colorado1 for permitting me to describe the fossils they discovered4 ,also ,dr4 ,robinson made available the draft of a short paper he had prepared on the tooth found in ,weld ,county1 ,colorado2 his work was facilitated by a grant from the ,university of ,colorado ,council on ,research and ,creative ,work4 ,i also gratefully acknowledge receipt of critical data and valuable comments from ,drs4 ,edwin ,c4 ,galbreath1 ,glenn ,l4 ,jepsen1 and ,malcolm ,c4 ,mc,kenna who is currently revising the ,paleocene apatemyids and studying the phylogenetic relationships of the family4 ,the prefixes of catalogue numbers used in the text identify fossils in the collections of the following institutions3 ,,ku1 ,museum of ,natural ,history1 ,the ,university of ,kansas1 ,lawrence2 ,princeton1 ,princeton ,museum1 ,princeton1 ,new ,jersey2 ,,ram-,,ucr1 ,raymond ,alf ,museum1 ,webb ,school of ,california1 ,claremont1 ,california 7the permanent repository for these specimens will be the ,university of ,california1 ,riverside72 and ,,ucm1 ,university of ,colorado ,museum1 ,boulder1 ,colorado4 ,the system of notations for teeth prescribed for use here is as follows3 teeth in the upper half of the dentition are designated by a capital letter and a number2 thus ,m#b is the notation for the upper second molar2 teeth in the lower half of the dentition are designated by a lower-case letter and a number2 thus p#b is the notation for the lower second premolar4 ,family ,,apatemyidae ,matthew1 #aiji ,genus ,sinclairella ,jepsen1 #aicd ,sinclairella dakotensis ,jepsen1 #aicd ,the type of the species1 ,princeton no4 #acehe1 was discovered in ,chadronian strata of the upper part of the ,chadron ,formation cropping out in ,big ,corral ,draw1 approximately #ac miles south-southwest of ,scenic1 in southwestern ,south ,dakota 7,jepsen1 #aicd1 p4 #bia74 ,detailed descriptions of the type specimen are given in papers by ,jepsen 7#aicd7 and ,scott and ,jepsen 7#aicf74 ,isolated teeth of ,chadronian age referable to ,sinclairella dakotensis have been discovered subsequently at a locality in ,nebraska and fossils of ,orellan age1 also referable to ,s4 dakotensis1 have been collected at two localities in ,colorado4 ,the sample from each locality is described separately4 ,sioux ,county1 northwestern ,nebraska ,material4--,,ram-,,ucr nos4 #cha1 left ,m#a2 #eih1 left m#b2 #ajjj1 right m#a2 #ajja1 right m#b2 #ajgi1 right m#b2 #afgd1 right ,m#b2 and #cjac1 left m#b4 ,locality and stratigraphy4--,these ,chadronian fossils were discovered by ,raymond ,alf and members of his field parties in several harvester ant mounds built in exposures of the ,chadron ,formation in ,sec4 #bf1 ,t #cc ,n1 ,r #ec ,w1 ,sioux ,county1 ,nebraska 7,alf1 #aifb1 and ,hough and ,alf1 #aieh74 ,this is ,,ucr locality ,v#edjc4 ,the collectors carefully considered the possibility that some of the fossils found in the ant mounds were collected from younger strata by the harvester ants and concluded this was unlikely 7,alf1 personal communication74 ,description and comments4--,the cusps of ,,ram-,,ucr no4 #cha1 a left ,m#a1 are sharp and the wear-facets resulting from occlusion with the lower dentition are small4 ,the paraconule is a low1 ill-defined cusp on the anterior margin of the crown2 a metaconule is not present4 ,a smooth stylar shelf is present labial to the metacone4 ,the crown was supported by three roots4 ,there are no interradicular crests4 ,the crown of ,,ram-,,ucr no4 #afgd1 a right ,m#b1 is heavily abraded and many morphological details of the cusps have been destroyed4 ,low interradicular crests linked the three roots of the tooth with a low1 central prominence4 ,as was the case with ,,ram-,,ucr no4 #cha1 no significant differences could be found in comparisons with illustrations of the teeth preserved in ,princeton no4 #acehe4 ,,ram-,,ucr nos4 #eih1 #ajja1 #ajgi1 and #cjac all appear to be m#b's4 ,the talonids of these teeth are not elongated1 their trigonids have quadrilateral outlines1 and the paraconids are small but prominent1 bladelike cusps4 ,the trigonid of ,,ram-,,ucr #ajjj is elongated and the paraconid is a minute cusp2 the tooth closely resembles the m#a of the type of ,sinclairella dakotensis4 ,logan ,county1 northeastern ,colorado ,material4--,,ku no4 #aabaj 7fig4 #a71 a fragment of a left maxillary containing ,p#d and ,m#a-b4 ,locality and stratigraphy4--,the fossil was found in the center of the ,w-#a_/b1 ,sec4 #ba1 ,t #aa ,n1 ,r #ec ,w1 ,logan ,county1 ,colorado1 444 in the bed below ,agnotocastor bed1 ,cedar ,creek ,member4444 7,ronald ,h4 ,pine1 #aieh1 field notes on file at the ,university of ,kansas74 ,the bed so defined is part of unit #c in the lower division of the ,cedar ,creek ,member1 as subdivided by ,galbreath 7#aiec3be7 in stratigraphic section ,,xii4 ,the fauna obtained from unit #c is of ,orellan age4 ,illustration3 ,,fig4 #a4 ,sinclairella dakotensis ,jepsen1 ,,ku no4 #aabaj1 fragment of left maxillary with ,p#d and ,m#a-b2 ,orellan1 ,logan ,county1 ,colorado2 drawings by ,mrs4 ,judith ,hood3 a1 labial view2 b1 occlusal view2 both approximately #i4 ,description and comments4--,p#d of ,,ku no4 #aabaj has a large posterolingual cusp separated from the main cusp by a distinct groove1 which deepens posteriorly4 ,the posterolingual cusp is supported by the broad posterior root4 ,p#d of the type specimen of ,sinclairella dakotensis is described 7,jepsen1 #aicd1 p4 #cib7 as having an oval outline at the base of the crown1 and a small1 posterolingual cusp4 ,a chip of enamel is missing from the posterior slope of the main cusp of the ,p#d of ,,ku no4 #aabaj4 ,the anterior slope of the main cusp is flattened1 possibly the result of wear1 and there is no evidence of a groove like that present on the ,p#d of the type specimen4 ,only a few differences were found between the molars preserved in ,,ku no4 #aabaj and their counterparts in the type specimen4 ,a stylar shelf is present labial to the metacone of ,m#a of ,,ku no4 #aabaj1 but1 unlike the type1 its surface is smooth and there is no evidence of cusps4 ,of the three small stylar cusps on the stylar shelf of ,m#b the smallest is in the position of a mesostyle4 ,the ,m#b lacks a chip of enamel from the lingual surface of the hypocone4 ,unlike the ,m#b of ,princeton no4 #acehe1 in occlusal view the posterior margin of the ,m#b of ,,ku no4 #aabaj is convex posterior to the metacone4 ,the anterior edge of the base of the zygomatic arch of ,,ku no4 #aabaj was dorsal to ,m#b4 ,the shallow oval depression in the maxillary dorsal to ,m#a might be the result of post-mortem distortion4 ,the molars preserved in ,,ku no4 #aabaj and their counterparts in the type specimen do not appear to be significantly different in size 7table #a7 or morphology of the cusps4 ,the only difference between the two specimens that might be of classificatory significance is the difference in size of the posterolingual cusp of ,p#d4 ,at present the range of intraspecific variation in the morphology of ,p#d has not been documented for any species of apatemyid4 ,the evolutionary trend or trends of the apatemyids 7,mc,kenna1 #aifj1 p4 #dh7 for progressive reduction of function of p#d probably were paralleled by similar trends in the evolution of the ,p#d4 ,if so1 the intraspecific variation in the morphology of ,p#d could be expected to be somewhat greater than that of the upper molars1 for example4 ,the morphological difference between the ,p#d's of the type of ,sinclairella dakotensis and ,,ku no4 #aabaj is not extreme and does not exceed the range of intraspecific variation that could be expected for this element of the dentition4 ,the close resemblances in size and morphology between the ,m#a-b of ,princeton no4 #acehe and ,,ku no4 #aabaj also favor identification of the latter as part of a member of an ,orellan population of ,sinclairella dakotensis4 ,weld ,county1 northeastern ,colorado ,illustration3 ,,fig4 #b4 ,sinclairella dakotensis ,jepsen1 ,,ucm no4 #bajgc1 right ,m#b2 ,orellan1 ,weld ,county1 ,colorado2 drawing by ,mrs4 ,judith ,hood3 occlusal view1 approximately #i4 ,material4--,,ucm no4 #bjagc 7fig4 #b71 is a right ,m#b4 ,locality and stratigraphy4--,the tooth was discovered at the ,mellinger locality1 ,sec4 #ag1 ,t #aa ,n1 ,r #fe ,w1 ,weld ,county1 ,colorado4 ,the ,mellinger locality is in the ,cedar ,creek ,member1 ,white ,river ,formation1 and its fauna is considered to be of ,orellan age 7,patterson and ,mc,grew1 #aicg1 and ,galbreath1 #aiec74 ,description and comments4--,,ucm no4 #bajgc1 which is more heavily abraded than ,,ku no4 #aabaj1 shows no evidence of a stylar cusp either anterolabial to the metacone or in the position of a mesostyle4 ,a small stylar cusp is present anterolabial to the paracone4 ,a notch that appears to have been cut through the enamel of the posterolabial corner of the crown could have received the parastylar apex of ,m#c4 ,a similar notch is not present on the ,m#b of ,,ku no4 #aabaj nor indicated in the illustrations of the ,m#b of ,princeton no4 #acehe4 ,the coronal dimensions of ,,ucm no4 #bajgc 7table #a7 do not appear to differ significantly from those of the ,m#b's of ,,ku no4 #aabaj and the type specimen of ,sinclairella dakotensis4 ,comments ,with the discovery of ,orellan apatemyids the geochronological range of the family in ,north ,america is shown to extend from the ,torrejonian through the ,orellan land-mammal ages4 ,the discoveries reported here enlarge the ,oligocene record of apatemyids to include not only the type specimen of ,sinclairella dakotensis1 a skull and associated mandible from ,south ,dakota1 but also seven isolated teeth1 representing at least two individuals1 from a ,chadronian fossil locality in ,nebraska and one specimen from each of two ,orellan fossil localities in northeastern ,colorado4 ,simpson 7#aidd3gc1 and #aiec3abg7 presented tabulations of the published records of ,american apatemyids and suggested the data indicated the populations of these mammals were of small size throughout the history of the family4 ,the few pre-,oligocene occurrences of apatemyids described subsequently 7note ,mc,kenna1 #aifj1 figs4 #c-aj1 and p4 #dh7 and occurrences described here tend to reinforce ,simpson's interpretation4 ,this interpretation may have to be modified to some degree1 however1 when current studies of collections of pre-,oligocene apatemyids are completed 7,mc,kenna1 personal communication74 ,although information concerning the evolutionary trends of ,american apatemyids has been published1 no data on the morphological variation in a population are available in the literature4 ,an adequate basis for evaluating the significance of the morphological differences between the ,p#d's of ,princeton no4 #acehe and ,,ku no4 #abaaj coupled with the similarities of their ,m#a-b's is lacking4 ,in the evolution of ,american apatemyids the ,p#d underwent reduction in size and1 apparently1 curtailment of function4 ,this history suggests the range of morphological variation of ,p#d in populations of ,sinclairella dakotensis could be expected to be greater than that of the molars and encompass the morphological differences between the ,p#d's of ,princeton no4 #acehe and ,,ku no4 #abaaj4 ,the difference in age of the ,chadronian and ,orellan fossils does not constitute proof that they pertain to different species4 ,although the identification is admittedly provisional until more fossils including other parts of the skeleton are discovered1 the ,orellan fossils described here are referred to ,sinclairella dakotensis4 ,,table #a4--,,measurements 7,,in ,,millimeters7 ,,of ,,teeth ,,of ,,sinclairella ,,dakotensis ,,jepsen4 ,p#d ,m#a ,m#b ---------------------------------------- ------------------------------- lengthwidthlength#awidth#alength#awidth# a ---------------------------------------- ---------------------------- ,princeton no4 #aceheb #b4a #a4a #d4j #c4g #c4d #d4g ,,ram no4 #cha #d4a #c4e ,,ram no4 #afgd #c4d #d4b ,,ku no4 #aabaj #b4d #a4f #c4i #c4e #c4h #d4a ,,ucm no4 #bajgc #c4f #d4a ---------------------------------------- ---------------------------- m#a m#b ---------------------------------- length width length width ---------------------------------- ,princeton no4 #acehec #c4e #b4d #c4g #b4h ,,ram no4 #ajjj #c4e #b4b ,,ram no4 #eih #c4h #b4f ,,ram no4 #ajja #c4f #b4f ,,ram no4 #ajgi #d4j #b4h ,,ram no4 #cjac #c4f #b4h ---------------------------------------- ------------------------------ ,footnote #a3 ,length defined as maximum dimension of the labial half of the crown measured parallel to a line drawn through the apices of paracone and metacone4 ,width defined as maximum coronal dimension measured along line perpendicular to line defined by apices of paracone and metacone4 ,footnote #b3 ,dimensions provided by ,dr4 ,glenn ,l4 ,jepsen4 ,footnote #c3 ,dimensions taken from ,jepsen 7#aicd3cjj74 ,literature ,cited ,,alf1 ,r4 #aifb4 ,a new species of the rodent ,pipestoneomys from the ,oligocene of ,nebraska4 ,breviora1 ,mus4 ,comp4 ,zool41 no4 #agb1 pp4 #a-g1 #c figs4 ,,galbreath1 ,e4 ,c4 #aiec4 ,a contribution to the ,tertiary geology and paleontology of northeastern ,colorado4 ,univ4 ,kansas ,paleont4 ,cont41 ,vertebrata1 art4 #d1 pp4 #a-abj1 #b pls41 #bf figs4 ,,hough1 ,j41 and ,,alf1 ,r4 #aieh4 ,a ,chadron mammalian fauna from ,nebraska4 ,journ4 ,paleon4 #cj3acb-adj1 #d figs4 ,,jepsen1 ,g4 ,l4 #aicd4 ,a revision of the ,american ,apatemyidae and the description of a new genus1 ,sinclairella1 from the ,white ,river ,oligocene of ,south ,dakota4 ,proc4 ,amer4 ,philos4 ,soc41 #gd3bhg-cje1 #c pls41 #d figs4 ,,mckenna1 ,m4 ,c4 #aifj4 ,fossil ,mammalia from the early ,wasatchian ,four ,mile fauna1 ,eocene of northwest ,colorado4 ,univ4 ,california ,publ4 in ,geol4 ,sci41 #cg3a-acj1 #fd figs4 ,,matthew1 ,w4 ,d4 #aiji4 ,the ,carnivora and ,insectivora of the ,bridger ,basin1 ,middle ,eocene4 ,mem4 ,amer4 ,mus4 ,nat4 ,hist41 #i3bhi-efg1 pls4 #db-eb1 #aah figs4 ,,patterson1 ,b4 and ,,mcgrew1 ,p4 ,o4 #aicg4 ,a soricid and two erinaceids from the ,white ,river ,oligocene4 ,geol4 ,ser41 ,field ,mus4 ,nat4 ,hist41 #f3bde-bgb1 figs4 #fj-gd4 ,,scott1 ,w4 ,b4 and ,,jepsen1 ,g4 ,l4 #aicf4 ,the mammalian fauna of the ,white ,river ,oligocene--,part ,i4 ,insectivora and ,carnivora4 ,trans4 ,amer4 ,philos4 ,soc41 n4 s41 #bh3a-aec1 #bb pls41 #g figs4 ,,simpson1 ,g4 ,g4 #aidd4 ,tempo and mode in evolution4 ,new ,york3 ,columbia ,univ4 ,press1 xviii #bcg pp41 #cf figs4 #aiec4 ,the major features of evolution4 ,new ,york3 ,columbia ,univ4 ,press1 xx #dcd pp41 #eb figs4 ,transmitted ,june #bd1 #aifc4