taxonID	type	description	language	source
F463DC79213DF413FC400CF4FBB1B0F3.taxon	diagnosis	Diagnosis: Differs from all other paucituberculatans in that the upper molars lack an enlarged, ‘ hypoconelike’, metaconule; the paracone is less reduced; the paracone and the metacone are less twinned to StB and StC + StD, respectively; StB much larger than StC + StD; distal end of entocristid in m 1 – 3 relatively high. Etymology: Barda, from La Barda locality, where the type specimen of the type species of the genus was collected; - lestes, Latin for ‘ thief’, ‘ pirate’ and, by extension, ‘ carnivorous’ (lestikos), a term that characterizes the generic name of several fossil and living Paucituberculata. Type species: Bardalestes hunco sp. nov. Distribution: Late Palaeocene and Early – Middle Eocene, South America.	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
F463DC79213AF411FC430CF4FDC2B4BB.taxon	description	(FIG. 2 A, B) Type: LIEB-PV 1135 (Fig. 2 A, B), a fragment of left maxillary with M 2 – 3, and roots and part of the crown of M 4. Hypodigm: The type only. Locality, horizon and age: La Barda, Paso del Sapo (Chubut Province, Argentina). Andesitas Huancache Formation, Early-Middle Eocene. Measurements: See Table 1. Diagnosis: Differs from all other paucituberculatans in that the upper molars lack an enlarged, ‘ hypoconelike’, metaconule; the paracone is less reduced; the paracone and the metacone are less twinned to StB and StC + StD, respectively; StB much larger than StC + StD. Description (Fig. 2 A, B): The M 2 and M 3 of the type specimen are very similar to each other, the M 3 being longer and wider than the M 2. Although its crown is badly broken, it can be seen that the M 4 (not shown in Fig. 2) was very short and narrow, and two-rooted. Its width is approximately half the width of M 3. The protocone of M 2 is comparatively wider than that of M 3. In both molars the anterobasal cingulum is narrow and lingually connected with the preparaconular crest. The trigon is ample and transversely long; in the M 2 the metacone is somewhat higher than the paracone, whereas in the M 3 both cusps are subequal in height. In both molars the protocone is slightly eccentric, as in the upper molar here referred to Bardalestes sp. (see below), it is not in line with the tips of the StB and the paracone. StA is small and very low, StB is comparatively enormous, suboval in section and connected by means of a crest to the immediately posterior cusp (StC + STD; see below). This latter cusp is much smaller and lower than the StB and is even more reduced and close to StB in the M 3 than it is in the M 2. The postmetacrista is longer than the preparacrista and is orientated parallel to the postparacrista. The apex of the centrocrista is deep and reaches externally the anterolingual slope of StC + StD. In both the M 2 and M 3 the metaconule is larger than the paraconule. Comments: One of the most striking features of the upper molars of Bardalestes hunco is the morphology, position, and relative size of StB. This cusp is very large, high and is clearly facing the paracone, even if it is slightly posteriorly shifted in comparison with other South American marsupials. The cusp immediately posterior to StB is much smaller and occupies an intermediate position between the StC and StD of other more generalized marsupials. Thus, it raises the question of the homology of this cusp in Bardalestes. Derorhynchid ‘ didelphimorphians’ show some features that ‘ anticipate’ the molar pattern of Paucituberculata: large (although not proportionally huge) StB, a deeply V-shaped centrocrista, winged metaconule that is larger than the paraconule, and molars with a salient hypoconid and, in some cases, a slightly labiolingually compressed entoconid. The morphology of the stylar area of the representatives of this family is worth analysing. In this respect, some indeterminate Derorhynchidae from Itaboraí are suggestive: specimen MNRJ 2506 - V exhibits, especially in the M 1, some proximity of the paracone to the StB, no reduction of the latter cusp and the reduction of the StC and StD, especially the latter. The same features can be seen in the indeterminate Derorhynchidae specimens MNRJ 2352 - V and MNRJ-V 2894 - V, DGM 813 - M, and MNRJ 2894 - V, all from the Itaboraí Basin. A morphological pattern similar to that occurring in the stylar region of Bardalestes can be even more clearly appreciated in the derorhynchid Pauladelphys, from the Middle Eocene of Antarctica and Early Eocene of Paso del Sapo (Goin, Tejedor & Abello, 2000, 2001). In the only known upper molar of Pauladelphys juanjoi (MLP 96 - I- 5 - 45), an isolated left M 1, a manifest closeness between the reduced StC and StD is observed, so that the latter cusp is relatively distant from the metastylar corner of the tooth. The same condition is seen in upper molars referable to Pauladelphys sp. from Eocene levels of Paso del Sapo (Tejedor et al., in press). In some of these specimens (e. g. LIEB-PV 1116, LIEB-PV 1114), StC and StD are almost subequal and twinned, so that their bases are fused. This pattern suggests that the cusp posterior to the StB of the Bardalestes specimens studied here may have been the result of the fusion of the stylar cusps StC and StD. The subsequent evolution of this cusp in the more derived Paucituberculata may have involved an increase in size and its setting apart from the StD. Interestingly, in caenolestids such as Stilotherium dissimile, the stylar cusp posterior to the StB (which we homologize here with StC + StD) maintains its relative size in the upper molar series: it is larger than the StB in the M 1, subequal to StB in the M 2, and smaller and closer to the StB in the M 3. Even though no M 1 s are known among the Bardalestes specimens described here, it can be seen that in the M 3 of this taxon the StC + StD is smaller and closer to the StB than in the M 2. In brief, from the assemblage of Paleogene South American ‘ opossum-like’ marsupials, the upper molar pattern that occurs in the derorhynchid Pauladelphys may be an indication of the process underwent by the earliest paucituberculatans. In the particular case of the stylar area, the small cusp posterior to the StB seems not to be either the StC or the StD but rather the result of the fusion of both cusps.	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
F463DC792138F410FEF50B23FAC7B2FE.taxon	materials_examined	Referred specimens: MLP 90 - II- 5 - 336, an isolated upper molar (M? 2; Fig. 2 C, D) lacking the metastylar area; MLP 90 - II- 5 - 335, an isolated left protocone; MLP 90 - II- 5 - 337, an isolated right protocone; MLP 90 - II- 5 - 300 (Fig. 2 E, F), an isolated right talonid. Locality, horizon and age: Easternmost part of the Southern Cliff of Colhué Huapi lake, Sarmiento Department, Chubut Province, Argentina. Las Flores Formation, Río Chico Group; Late Palaeocene (Itaboraian Age). Measurements: See Table 1. Description (Fig. 2 C, D): Even though broken and mostly missing the metastylar area, it is evident that MLP 90 - II- 5 - 336 is a wide molar (i. e. its labio-lingual diameter is larger than the mesio-distal one). The trigon basin is labio-lingually wide because of the deep centrocrista. The protocone is moderately developed; its tip is relatively centrally placed, that is, it is not aligned in a transverse axis with StB and the paracone. The preprotocrista is not symmetrical to the postprotocrista as the metaconule, larger than the paraconule, is posteriorly salient. Both the paracone and the metacone are worn down almost to their bases; from their respective sections it can be inferred that the paracone was only slightly smaller than the metacone. The preparacrista is subequal in length to the postparacrista and the premetacrista; it is almost transversally orientated with respect to the dental axis. The postparacrista and the premetacrista are subequal in length; they are not symmetrical to each other but instead the premetacrista is slightly more transverse to the dental axis. The postmetacrista has preserved only its proximal end which is parallel to the postparacrista; its preserved portion suggests that it was moderately developed. The paraconule is half the size of the metaconule; both cusps are ‘ winged’, i. e. they have pre- and postconular cristae. The preparaconular crest continues labially in the anterobasal cingulum; the postparaconular crest is reduced or absent; in turn, and even though worn, the premetaconular crest seems to have been longer and more subhorizontal than the postmetaconular one, which descends abruptly downwards and posterolabially. The stylar shelf is moderately developed and is deeply penetrated by the centrocrista at its central portion. The ectoflexus is almost undistinguishable; StB and StC + StD are very close together and have no labial emargination. A tiny cuspule which is very low and subcircular in section can be observed behind the labial apex of the centrocrista. This cuspule is not located near the labial face of the tooth, as are other stylar cusps, but instead it is internally placed on the stylar shelf. The most conspicuous feature of the remaining stylar cusps is the very large size of StB, which occupies most of the anterior half of the stylar shelf. StB is not only large but also very high; it is suboval in section, as it is slightly labiolingually compressed. Its labial and lingual slopes are steep; anteriorly it has a rounded edge, whereas the posterior one is crest-shaped, trenchant in aspect. The metastylar area is broken behind StC + StD. At the lingual slope of StB a minute wrinkle can be observed, just posterior to the labial end of the preparacrista. Compared to other ‘ opossum-like’ marsupials, it is evident that the lingual slope of StB and the labial slope of the paracone in Bardalestes are very close to each other relative to the total width of the upper molar (see the reconstruction of the paracone in Fig. 2 D). The anterolabial corner of the tooth, poorly preserved, is rather small; a moderately developed but very low StA can be inferred from it. The anterior cingulum is poorly developed. Three additional specimens are also referred to Bardalestes sp. Two of them (MLP 90 - II- 5 - 335 and MLP 90 - II- 5 - 337) consist of isolated protocones, one left and the other right; they are roughly similar, in size and morphology, to the protocone of the already described upper molar. The third specimen (MLP 90 - II- 5 - 300; Fig. 2 E, F) consists of a fragmentary right molar preserving the talonid and part of the posterior wall of the trigonid. Judging from the preserved portion of the metacristid, the trigonid was much higher than the talonid. The latter has a salient hypoconid, a small, laterally compressed entoconid, and a reduced hypoconulid located posterior to the entoconid; the talonid basin is relatively deep; the cristid obliqua ends anteriorly near the labial base of the protoconid; the distal end of the entocristid in m 1 – 3 is relatively high (Fig. 2 F). There is a short postcingulum at the posterior face of the talonid; the posthypocristid is almost transverse to the dental axis. One additional specimen can also be also referred to Bardalestes sp.: MLP 90 - II- 5 - 332. This specimen consists of an isolated talonid belonging to a mx. Its morphology resembles that of MLP 90 - II- 5 - 300. The specimen was polished in order to examine its enamel structure (specimen KOE 2991; Koenigswald & Goin, 2000). As in the upper and lower molars of the Caenolestidae, the enamel in Bardalestes shows prisms that are orientated more or less straight between the enamel – dentine joint and the outer enamel surface. A thick interprismatic matrix orientated at an angle with the prisms could be observed. This pattern is common among other generalized ‘ opossum-like’ marsupials (Koenigswald & Goin, 2000: 149). Comments: Among the ‘ opposum-like’ marsupials collected from the Las Flores Formation, represented by more than 700 isolated teeth, there are a few taxa of very small size. The specimens here assigned to Bardalestes sp. are among the smallest of them. Specimen MLP 90 - II- 5 - 300 has the hypoconulid twinned to the entoconid, a synapomorphy of Late Cretaceous and younger marsupials (Kielan- Jaworowska, Cifelli & Luo, 2004). In addition, the laterally expanded hypoconid, and the labio-lingually compressed entoconid are features diagnostic of the Paucituberculata (see below). Specimens MLP 90 - II- 5 - 335 and MLP 90 - II- 5 - 337 are almost identical in size and morphology. In turn, specimen MLP 90 - II- 5 - 300, an isolated lower molar fragment, matches in size and shape the expected pattern for an occlusal antagonist to the type specimen. In short, their size, morphology, and inferred occlusal relationships concur in assigning all specimens to the same taxon. The size and morphology of specimen LIEB-PV 1135, type of Bardalestes hunco, are very similar to those of specimen MLP 90 - II- 5 - 336. The greatest differences between the latter and LIEB-PV 1135 are the following: StC + StD larger in the latter, which in addition lacks the cuspule posterior to the centrocrista apex, and, especially in M 2, more posteriorly located with respect to the StB. Regarding their size, specimen MLP 90 - II- 5 - 336 is slightly larger than LIEB-PV 1135. In all other features, the M 3 of LIEB-PV 1135 is indistinguishable from specimen MLP 90 - II- 5 - 336, for which reason we assume the latter to be an M 3 as well. The finding of new material could prove that the small differences between them fall within the variability range of a single species, as the greatest difference is the increased size of the cusp posterior to the StB (which we consider homologous to the fusion of cusps StC + StD).	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
F463DC792139F410FC080EEBFADDB4C0.taxon	diagnosis	Diagnosis: As for the type and only known species. Etymology: Rio - for the state of Rio de Janeiro, Brazil, where are located the fossiliferous outcrops of the Itaboraí Basin; - lestes, Latin for ‘ thief ’, ‘ pirate’ and, by extension, ‘ carnivorous’ (lestikos), a term that characterizes the generic name of several fossil and living Paucituberculata. Type species: Riolestes capricornicus sp. nov. Distribution: Late Palaeocene, South America.	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
F463DC792139F41FFC8108A1FC2DB62A.taxon	etymology	Etymology: In reference to the geographic placement of the fossil locality, near the Southern Tropic of Capricorn. Locality, horizon, and age: São José de Itaboraí, State of Rio de Janeiro, Brazil (22 ° 44 ′ 51 ″ S, 42 ° 51 ′ 21 ″ W); Itaboraí Basin, Late Palaeocene (Itaboraian Age). Type: MCN-PV 1790 (Fig. 3), an isolated m 1. Hypodigm: The type only. Measurements: See Table 1. Diagnosis: Differs from the remaining Paucituberculata in the following combination of characters: large size, m 1 with reduced paraconid, mesially placed; persistence of the paracristid notch, vestigial anterobasal cingulum, trigonid basin absent; metaconid well displaced posteriorly. Description: The most distinctive features of this molar are its proportionally large size, reduced paraconid, high protoconid, backwardly placed metaconid, absent trigonid basin, labially salient hypoconid (i. e. laterally expanded), and wide talonid basin. The paraconid is poorly developed, much less than the metaconid; its anterior face is flat. The anterobasal cingulum, although vestigial, runs at a short distance below and labial to the paraconid. The metaconid is moderately developed and is set close to the protoconid but quite posterior to it. Thus, the metacristid (postprotocristid + postmetacristid) is short, high, and in occlusal view is obliquely placed with respect to the dental axis. The paracristid (preprotocristid + postparacristid) is sharp, trenchant, and runs steeply downwards, almost subvertical, from the protoconid to the paraconid. The paracristid notch is placed just posterior to the paraconid. The talonid is much wider than the trigonid; its basin is well bound by the pre-entocristid, the cristid oblique, and the posthypocristid. The hypoconid and the entoconid are subequal in height, the latter being laterally compressed; the hypoconulid is located posterolingually relative to the entoconid, and is projected backwards. The cristid obliqua reaches anteriorly up to a point below the notch of the metacristid; it is not parallel to the labial face of the tooth but instead narrows the talonid basin anteriorly. There is no postcingulum. Below the crown, the anterior root is smaller than the posterior one. The cristid obliqua is worn on its anterodorsal edge, as well as the posthypocristid near the hypoconulid and the entoconid at its labial face. Comments: Riolestes capricornicus can be considered a marsupial on the basis of the pairing of the entoconid and the hypoconulid. Its most distinctive features agree well with those expected for a member of the Paucituberculata: labially projected hypoconid and laterally compressed entoconid (see below). An additional feature, the metaconid clearly posterior to the protoconid, occurs in the first molar in most Paucituberculata – except in Stilotherium, Phonocdromus, and Pichipilus. Finally, the paraconid of m 1 is reduced in all paucituberculatans, as in the type of Riolestes capricornicus. Although not frequent among more modern marsupials, the location of the metaconid somewhat posterior with respect to the protoconid appears not only in the m 1 but also in the dp 3 s of several different lineages, including some very generalized forms such as Alphadon. Cifelli (1994), referring to several deciduous molars tentatively referred to Alphadon perexiguus, pointed out that ‘ ... the trigonid is broadly open lingually, with the paraconid and metaconid more anteriorly and posteriorly placed, respectively, than on the permanent molars. The paraconid and metaconid are weakly developed (...) As usual among marsupial dP 3 s, the cristid obliqua extends anterolingually as a crest to the tip of the metaconid, resembling the distal metacristid (...) seen in permanent molars of primitive Tribosphenida’ (Cifelli, 1994: 124; Cifelli & de Muizon, 1998). The posterior placement of the metaconid with respect to the protoconid is also verified in the permanent molars of some Early Palaeocene South American taxa, such as the polydolopimorphian Roberthofftetteria nationalgeographica. Among the most primitive Sparassodonta, such as some Hathliacynidae, the reduction of the metaconid in m 1 occurs together with its posterior placement in the trigonid. In some Microbiotheriidae, such as Pachybiotherium acclinum, Eomicrobiotherium gaudry, and Microbiotherium gallegosense, the posteriorly ‘ shifted’ metaconid in m 1 occurs together with the mesial ‘ shift’ of the paraconid, as in Riolestes. Some early Didelphimorphia, such as Itaboraidelphys camposi, also show a slight posterior displacement of the metaconid. Finally, among the Paucituberculata Caenolestidae and, especially, Palaeothentidae, the m 1 metaconid also shows a displacement similar to that of Riolestes. In short, the posterior displacement of the metaconid is not exclusive to the marsupial dp 3 but also occurs in several permanent molars in various lineages, noticeably in the m 1 of most Paucituberculata. Luckett & Hong (2000) demonstrated that the dp 3 is vestigial and extremely reduced in paucituberculatans, which is obviously not the case in MCN-PV 1790. Finally, the positions and relative sizes of the trigonid cusps in Riolestes capricornicus match well those of the m 1 of paucituberculatans. Riolestes capricornicus and Bardalestes sp. from Las Flores are contemporary paucituberculatans. Differences between them include the following features: Riolestes capricornicus triples Bardalestes sp. in size; its type specimen differs from the lower molar referred to Bardalestes sp. in that there is a less salient hypoconid, the entoconid is comparatively smaller, the hypoconulid is less proximate to the entoconid (in Bardalestes it is almost immediately posterior to the entoconid), it has a shallower talonid basin, and it lacks a posterobasal cingulum. All these differences warrant a generic distinction between these taxa.	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
F463DC792132F419FC360DF3FEA8B62A.taxon	description	The present analysis yielded several unexpected results regarding the traditional systematic concepts for Paucituberculata marsupials: (1) the exclusion of Pliolestes from the ‘ Pichipilinae’ (sensu Marshall et al., 1990) and their grouping together with the Caenolestidae Stilotherium, Caenolestes, and Rhyncholestes; and (2) the grouping of Pichipilus and Phonocdromus as sister taxa to Palaeothentidae + Abderitidae clade. These conclusions are discussed separately. 1. In his original description of Pliolestes tripotamicus, Reig (1955) pointed out the close affinities of this genus with Phonocdromus (see also Pascual & Herrera, 1973). Subsequently Marshall (1980), in his review of the South American Caenolestoidea, included Pliolestes in the new tribe Pichipilini, together with Phonocdromus and Pichipilus. Finally, Marshall et al. (1990) raised this taxon to a subfamiliar rank: Pichipilinae (Caenolestidae). The results of our analysis support the hypothesis that Pliolestes does not form a monophyletic group with Pichipilus and Phonocdromus, but instead with the ‘ Caenolestini’ sensu Marshall (1980). Actually, the concept of Caenolestidae proposed in this paper is restrained to the following genera: Caenolestes, Pliolestes, Rhyncholestes, and Stilotherium, and is characterized by the following synapomorphies (see Fig. 7): high entocristid in m 1 – 3 (171), curved entocristid in m 1 - 3 (191), m 4 single-rooted and greatly reduced in relation to m 3 (251). Stilotherium is the sister taxon to (Pliolestes (Caenolestes + Rhyncholestes). The latter group is supported by the synapomorphy: entoconid posteriorly located (201). Rhyncholestes plus Caenolestes share one synapomorphy: very shallow metacristid in m 2 – 3 (291). Pliolestes shows one homoplasic character shared with the representatives of the Palaeothentoidea (see bellow): para- and metaconids of m 3 very close or fused (231). Note that neither the living caenolestid Lestoros nor the extinct Pseudhalmarhiphus were considered in this paper. The holotype (and only known remain) of the Deseadan species Pseudhalmarhiphus guaraniticus Ameghino (1899) (only species of the genus) has disappeared from Argentinean collections, so almost nothing can be said of its affinities. Marshall (1976, 1980), based on illustrations of the holotype published by Ameghino (1894), said that ‘ ... Pseudhalmarhiphus is structurally similar to and is probably ancestral to Stilotherium dissimile ’ (Marshall, 1980: 35). Finally the generic validity of Lestoros inca (Thomas, 1917) – the only species of this genus geographically restrained to the Andean region south of Peru – has been discussed (e. g. Simpson, 1970). Marshall (1980) stated that Caenolestes and Lestoros can hardly be distinguished. 2. Another result of this analysis is the exclusion of Pichipilus and Phonocdromus from the Caenolestidae and their grouping as sister taxa of palaeothentids + abderitids. The features that, according to Marshall (1980), justify regarding the ‘ Caenolestinae’ – including Stilotherium, Pseudhalmarhiphus, Caenolestes, Lestoros, Rhyncholestes, Pliolestes, Phonocdromus, and Pichipilus – as a monophyletic group, are the following: (1) doublerooted and functional p 2; (2) p 3 large, double-rooted and subequal or higher than the trigonid of m 1; (3) M / m 1 – 4 tuberculo-sectorial, without lophs in unworn molars; (4) m 1 with prominent metaconid; (5) nonmodified talonid and trigonid areas; (6) m 2 – 3 with differentiated trigonids and talonids; (7) talonid much larger than trigonid in occlusal view; (8) M 1 – 3 with metacone (‘ intermediate conule’ sensu Marshall, 1980) labially orientated; (9) M 1 quadritubercular; (10) neither P 3 nor M 1, p 2 or m 1 are modified as sectorial teeth; (11) presence of an antorbital vacuity between the nasal, maxillary, and frontal. However, none of these features are synapomorphies within the Paucituberculata, nor are present in all ‘ Caenolestinae’ taxa: (1) a doublerooted and functional p 2 is the generalized condition in all marsupials; (2) p 3 is quite small compared with the development of this tooth in the Palaeothentidae and Abderitidae – and, in any case, its development is only moderate with respect to other marsupial groups; (3) the molars of the Palaeothentidae are also tuberculo-sectorial and lack lophs; (4) in the Palaeothentidae the metaconid is also prominent; (5) the statement that that the trigonid and talonid areas in the m 1 of ‘ Caenolestidae’ are ‘ non-modified’ was not verified in our study: in Caenolestes, as well as in Rhyncholestes, Stilotherium, and Pliolestes, the para- and metaconids are separated and the trigonid lacks a basin; (6) trigonids and talonids are differentiated in all the Paucituberculata and, besides, both Pichipilus and Phonocdromus share the same differentiation between both regions as the Palaeothentidae; (7) talonid wider than trigonid is not an exclusive feature of ‘ Caenolestidae’ sensu Marshall (1980); rather, as it has been pointed out, it is already present in a generalized form of Paucituberculata: Riolestes capricornicus; (8) the metacone, when present, is always labially orientated, adjacent to the stylar cusp D; (9) M 1 is quadritubercular in all Paucituberculata – although with slight variants; see Character Analysis; (10) ‘ P 3, M 1, p 2, and m 1 not differentiated in sectorial teeth’ is the generalized condition in all marsupials; (11) finally, the presence of the vacuities cannot be verified in Pichipilus or Phonocdromus (see Character Analysis). This latter character is important because, as Marshall (1980: 127) himself recognized, despite the other features listed in his diagnosis, this one would be actually the only synapomorphy in common with his ‘ Caenolestinae’ (‘ Caenolestini’ + ‘ Pichipilini’). As mentioned above, the only specimen of ‘ Pichipilini’ in which a skull has been preserved, with the rostrum area, is MLP 66 - I- 17 - 204, assignable to Pichipilus centinelus; however, the presence or absence of antorbital vacuities cannot be determined because of the damage to the material (contra Marshall & Pascual, 1977). Thus, Pichipilus and Phonocdromus do not show derived features in common with the ‘ Caenolestinae’ sensu Marshall et al. (1990), but with the Palaeothentidae and Abderitidae, with which they form a monophyletic group. Both genera, here included within the family Pichipilidae (new rank) do not show affinities with Pliolestes, a caenolestid related to the Rhyncholestes + Caenolestes clade. The Pichipilidae are the sister group of palaeothentids + abderitids. In turn, pichipilids, palaeothentids, and abderitids, here included within the Superfamily Palaeothentoidea nov., are the sister group of the Caenolestoidea. In our concept, this last taxon includes a single family: Caenolestidae, containing the following genera: Stilotherium, Pseudhalmarhiphus, Caenolestes, Lestoros, Rhyncholestes, and Pliolestes.	en	Goin, Francisco J., Candela, Adriana M., Abello, M. Alejandra, Oliveira, Edison V. (2009): Earliest South American paucituberculatans and their significance in the understanding of ‘ pseudodiprotodont’ marsupial radiations. Zoological Journal of the Linnean Society 155 (4): 867-884, DOI: 10.1111/j.1096-3642.2008.00471.x, URL: https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2008.00471.x
