taxonID	type	description	language	source
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	description	(Figs. 2 C – I 2, 3 A – D).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	materials_examined	Referred material Lower third molars with fragmented roots and slight wear on first and second lophids that might belong to the same individual, since wear stages are very similar (MHNG GEPI V- 3473 and MHNG GEPI V- 3475, Fig. 2 C – D), fragmented lower left third molar with no wear and no roots (MHNG GEPI V- 3478, Fig. 2 E), two upper third molars with fragmented roots and no wear that might belong to the same individual (MHNG GEPI V- 3474, Fig. 2 F – G), fragment of a left mandibular ramus with a third molar with advanced wear stage (PIMUZ A / V 4092, Fig. 2 H 1 – H 2), lower left third molar with advanced wear, roots and fragments of mandible (PIMUZ A / V 4161, Fig. 2 I 1 – I 2), lower right third molar with intermediate wear and fragmented third pretrite (MHNG GEPI V- 3479, Fig. 3 A), lower left third molar with intermediate wear and fragmented at anterolingual bor- der (MHNG GEPI V- 3502, Fig. 3 B), fragmented upper left first molar with intermediate wear (MHNG GEPI V- 3491, Fig. 3 C, and - 3486), and fragmented lower right first molar missing part of the first lophid, with intermediate wear (MHNG GEPI V- 3480). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	description	Description and comparisons All molars are bunodont with the characteristic double to simple trefoil wear pattern of Notiomastodon platensis (i. e., MHNG GEPI V- 3502, - 3491, - 3486, and - 3480). Te third molars are pentalophodont and have a variable distal cingulum, and those teeth with no wear or intermediate wear show a range from 57 to 64 cups, which is within the Notiomastodon ’ s range of 35 to 82, as described in the literature (Mothé et al., 2017 c). For total length of the complete molars see Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	discussion	Remarks Isolated molars are the most common fossils of the South American proboscideans, but unfortunately they are not fully diagnostic for Notiomastodon and Cuvieronius when isolated and / or fragmented, since most features are variable and overlapping (Mothé et al., 2017 b). Te total number of cusps in complete and well-preserved third molars has been successfully used to differentiate both genera (Mothé & Avilla, 2015; Mothé et al., 2017 c). Cuvieronius hyodon presents third molars with a number of cusps ranging from 33 to 60, whereas in Notiomastodon, the number of cusps range between 35 and 82 (see Mothé et al., 2017 c). As mentioned above, the complete third molars we are describing here show a range from 57 to 64 cusps, which is in the range of Notiomastodon. Te fragmentary nature of some specimens does not allow access to the complete number of cusps but, since the wear pattern on pretrites and postrites is complex (double – trefoil), it suggests that the number of cusps of some specimens might be higher (e. g., PIMUZ A / V 4092, 4161, MHNG GEPI V- 3502). Te specimens reported herein are tentatively assigned to Notiomastodon cf. N. platensis. Gomphotheriidae indet. (Fig. 3 E – O). Referred material Five broken and incomplete teeth with extreme wear (PIMUZ A / V 4105, 4136, 4185, 4279), left distal humerus epiphysis (PIMUZ A / V 4159), left radius (MHNG GEPI V- 3477), left femur (PIMUZ A / V 4158),? right patella (MHNG GEPI V- 3490), right tibia (PIMUZ A / V 4160), right calcaneus (MHNG GEPI V- 3505), navicular, right trapezoid,? metatarsal III and? metacarpal III (MHNG GEPI V- 3494), and rib fragment (MHNG GEPI V- 3499). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	description	Description and comparisons PIMUZ A / V 4105 is a fragment of hemimandible with incomplete and fragmented crown of a m 2, and an indeterminate tooth fragment in a poor state of preservation. Number PIMUZ A / V 4279 corresponds to an incomplete and extremely worn molar, possibly M 2 or m 2, and two other molariform fragments of indeterminate position. PIMUZ A / V 4185 is represented by three fragmented and isolated lophs, possibly from the same individual. Specimen PIMUZ A / V 4136 is a broken molar with extreme wear of indeterminate position (Fig. 3 E). Postcranial appendicular elements are represented by a left distal epiphysis of a humerus (PIMUZ A / V 4159, Fig. 3 F), left radius of 567 mm in length missing the proximal epiphysis (MHNG GEPI V- 3477, Fig. 3 G), complete left femur with a total length of 1045 mm (PIMUZ A / V 4158, Fig. 3 I 1 – I 2), diaphysis of a right tibia of 445 mm in length (PIMUZ A / V 4160, Fig. 3 K), a? right patella (MHNG GEPI V- 3490, Fig. 3 J), a complete right calcaneus (MHNG GEPI V- 3505, Fig. 3 L 1 – L 2), navicular, right trapezoid,? metatarsal III and? metacarpal III (MHNG GEPI V- 3494, Fig. 3 M 1 – O). A fragmented right rib is the sole element from the axial skeleton (MHNG GEPI V- 3499, Fig. 3 H).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	discussion	Remarks Te state of preservation of the dental remains and the lack of diagnostic characters on the postcranial bones (Mothé & Avilla, 2015), do not allow to classify these specimens beyond the family level. Tere are no detailed morphometric studies on postcranial elements of Cuvieronius and Notiomastodon that may demonstrate the taxonomic significance of postcranial features. Considering the known geographical distribution of Notiomastodon that includes the Pampean region (Alberdi & Prado, 2022; Lucas, 2013; Mothé & Avilla, 2015; Mothé et al., 2017 a, b, c), the assignment to this taxon is ultimately likely. Artiodactyla (Owen, 1848). Camelidae Gray, 1821 Lama Cuvier, 1800 Lama guanicoe (Müller, 1776). (Fig. 4 A 1 – A 3). Referred material An almost complete mandible with both incomplete lower molar series and without coronoid and angular processes and condyle (PIMUZ A / V 4089). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	description	Description and comparisons Te mandible is gracile, broken at the level of both coronoid and angular processes. Te dorsal and ventral margins of the horizontal ramus are almost parallel to each other. Te lingual surface of the horizontal ramus is flat and the labial side is slightly convex. Both rostral and caudal mental foramina are not observed due to embedded sediment on the bone surface. Tere are five incisors. Caniniforms are not preserved. Te dental formula shows the alveoli of premolars in the third and fourth positions as in Lama guanicoe and Hemiauchenia paradoxa (Lynch et al., 2020). Te right hemimandible has m 1 – m 3, while the left preserving m 1 – m 2 series, being broken at level of the anterior root of the m 3 (Fig. 4 A 2). Occlusal length and width, respectively, are 13 mm and 10 mm in m 1, 18 mm and 11 mm in m 2, and 23 mm and 10 mm in m 3. Te right m 1 – m 3 series length is 54 mm. Tese selenodont molars are characterized by having well-developed anterior stylids or “ Llama buttresses ” (protostylids and parastylids), although on m 3 these are weakly prominent labio-lingually. Te anterior fossa (trigonid fossa, Scherer et al., 2007) on m 1 is not seen due to the advanced wear, making this specimen to correspond to an adult with " wear stage 4 " in the classification of Breyer (1977). All fossae are closed, which is more typical of Camelidae than Cervidae (the latter group has the distal end of the anterior fossetid lingually opened) (Fig. 4 A 3). Te labial lophids are U-shaped (e. g., Gasparini et al., 2017; Scherer et al., 2007), and the second lobe of each molar is set off from the anterior lobe by a pronounced vertical and deep labial flexid. Te third lobe (hypoconulid) is smaller and oval in outline (Fig. 4 A 3).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	discussion	Remarks PIMUZ A / V 4089 displays many morphological characters consistent with South American Camelidae (see Lynch et al., 2020; Scherer, 2013). Te morphological and morphometric features reported above allow us to assign PIMUZ A / V 4089 to Lama guanicoe. Te fossil record of Lama is known since the Late Pleistocene deposits in Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, and Uruguay (Scherer, 2013; Tonni & Politis, 1980, and references therein). However, according to Wheeler (1995), the records of Lama from Ecuador and Colombia need confirmation. Lama has been widely recorded from Holocene deposits in the southern region of Argentina, although its record at different sites from the middle and lower Paraná River basin during this time has been questioned (see Politis et al., 2011). Menegaz and Ortiz Jaureguizar (1995) reported the existence of a fossil Lama anatomically indistinguishable from L. guanicoe from Pleistocene deposits of the North Pampa (Buenos Aires Province), with dimensions similar to the range of Hemiauchenia. Lynch et al. (2020) reported a well-preserved South American Lamini partial skeleton from the Early Pleistocene of Argentina with a new cladistic analysis of the Camelinae subfamily. Tis specimen (PIMUZ A / V 4165) was also collected by Santiago Roth in the right cliff of the Paraná River, San Nicolás locality (Buenos Aires Province) (Roth, 1889). According to the hypothesized phylogenetic position by Lynch et al. (2020), PIMUZ A / V 4165 is more closely related to L. guanicoe and Vicugna vicugna than to H. paradoxa. On the other hand, some morphological, morphometric and few molecular considerations on Lama taxonomy recognize the extinct Lama gracilis as a valid Lamini taxon of a gracile vicuña from the Late Pleistocene – Early Holocene of Patagonia and Tierra del Fuego (Menegaz, 2000; Menegaz et al., 1989; Metcalf et al., 2016). Nevertheless, there is no consensus regarding the taxonomic status and phylogenetic context between the living and fossil camelids from South America (see Cajal et al., 2010; Cartajena et al., 2010; Miller, 1924; Stanley et al., 1994; Weinstock et al., 2009). Tus, these hypotheses must be tested by more molecular, morphological and morphometric studies. At present, two living species of wild Lamini Camelidae have been recognized, L. guanicoe and V. vicugna, which are restricted to environments with arid to semi-arid conditions from the north-central area of the Andes and Patagonia (8 º S to 55 º S), and also between altitudes that range from sea level to 4000 m (Baldi et al., 2008; Franklin, 1982; Lichtenstein et al., 2008; Wheeler, 1995). Hemiauchenia Gervais & Ameghino, 1880 Hemiauchenia paradoxa Gervais & Ameghino, 1880 (Fig. 4 B 1 – B 6). Referred material Anterior region of the skull and left maxilla with P 3 – M 3, left hemimandible with three pair of lower incisors and p 3 – m 3 from the same individual (PIMUZ A / V 4287). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	description	Description and comparisons Cranial remains including fragmented premaxilla and part of the maxilla preserved up to the area of the infraorbital foramen, with right I 3 and a caniniform (Fig. 4 B 3). Te left maxilla shows the P 3 – M 3 series with slight wear and M 3 erupting. Both fossetids in M 3 are opened (Fig. 4 B 2). Te occlusal length of the molar series is 82 mm. PIMUZ A / V 4287 corresponds to a young-adult camelid (Breyer, 1977). Te left hemimandible has three lower incisors (i 1 – i 3) on both sides, a caniniform (that is separated from the incisors by a diastema), and p 3 – m 3 series (Fig. 4 B – B 6). Te occlusal length of the molar series is 105 mm. Te lingual surface of the horizontal ramus is flat and the labial side is slightly convex (Fig. 4 B 4). Both rostral and caudal mental foramina are observed in labial view of the hemimandible. Te former is located distally to the caniniform (Fig. 4 B 5). Te left caniniform is preserved and both m 3. Te p 3 – m 2 series has labial U-shaped lophids with closed fossae (Gasparini et al., 2017; Scherer et al., 2007). Te second lobe of each cheek tooth is set off from the anterior lobe by a deep labial flexid. Te third lobe (hypoconulid) is smaller and oval in outline. Te anterior stylids (protostylids and parastylids) of lower molars are not observable because the teeth are partially inside their alveoli. All dental fossae are closed, with the exception of those in m 3, showing both fossetids mesiodistally opened. PIMUZ A / V 4287 corresponds to a young-adult individual with permanent dentition already erupted but almost no wear (" wear stage 1 " following Breyer, 1977).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B3BFFDE6B10AAD2FD005ECF.taxon	discussion	Remarks Hemiauchenia represents one of the largest Lamini camelids that inhabited South America during the Late Pliocene to Pleistocene (Gasparini et al., 2017; Scherer, 2013). It is known from outcrops mostly of Argentina and Uruguay (Cione & Tonni, 1999; Cione et al., 1999, 2015; Gasparini et al., 2017; Menegaz & Ortiz-Jaureguizar, 1995; Ubilla, 2004; Ubilla & Perea, 1999). In contrast, Palaeolama, has been reported from Early Pleistocene deposits of Bolivia (MacFadden & Shockey, 1997; Marshall et al., 1984), and Late Pleistocene deposits of Bolivia, Brazil, Chile, Ecuador, Paraguay, Peru and Venezuela (Carrillo-Briceño, 2015; Cartelle et al., 1989; Marshall et al., 1984; Scherer, 2013). López-Aranguren (1930) synonymized H. paradoxa to Hemiauchenia major, and Cabrera (1932, 1935) and Rusconi (1931) attributed the former taxon to Palaeolama weddelli. Later investigations revalidated H. paradoxa, although included in another genus: Palaeolama (see Hoffstetter, 1952). Webb (1974) and Scherer (2013) considered both Hemiauchenia and Palaeolama as valid taxa, but suggested that H. paradoxa is restricted to Argentina and H. major to northeastern Brazil. Nevertheless, some authors considered that the Brazilian forms correspond to Palaeolama major (Bergqvist, 1993; Cartelle et al., 1989; Guérin et al., 1990; Souza-Cunha, 1966). Some taxonomic studies suggested that morphological differences between H. paradoxa and P. major do not support a taxonomic separation, but rather indicate intraspecific variations (Cartelle, 1992, 1999). However, more recently Scherer (2009, 2013) supported the taxonomic validity of both genera for South America, with the recognition of at least three Palaeolama species: P. weddelli, P. major, and P. hoffstetteri. In contrast, H. paradoxa is considered the only valid species for this genus.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	(Fig. 4 C 1 – G 2).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	materials_examined	Referred material Two fragments of right hemimandibles with deciduous dentitions (PIMUZ A / V 4186), right hemimandible body with m 1 – m 3 partially preserved and left hemimandible body with dp 4 – m 2 partially preserved (PIMUZ A / V 4187), right hemimandible with p 3 – p 4 (PIMUZ A / V 4192), left hemimandible body with talonid of m 2 and the entire m 3 (PIMUZ A / V 4195), right hemimandible body with m 2 – m 3 partially preserved (PIMUZ A / V 4201), two fragments of right and left hemimandibles with deciduous and permanent dentitions (PIMUZ A / V 4200), right hemimandible body with m 1 – m 3 (PIMUZ A / V 4257), isolated m 2 (PIMUZ A / V 4127, PIMUZ A / V 4179, A / V 4189), and isolated lower teeth (PIMUZ A / V 4196, PIMUZ A / V 4255). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 4186 corresponds to two rights hemimandibles with dp 4 without wear and erupting m 1. Te dp 4 is similar to teeth of the molariform series with three lobes. Te cusps are still separated and have no wear. Te fossetids are mesiodistally opened (Fig. 4 C 1). PIMUZ A / V 4187 is represented by two fragments of a mandible probably from the same individual. Te right hemimandible has the talonid of the m 1 – m 3 partially preserved (Fig. 4 D 1 – D 2). Te left hemimandible has a dp 4 and both trigonids of m 1 – m 2 fractured and cover by carbonate concretions. In this specimen the molars have all fossae closed and labial lophids with U-shaped. Left dp 4 is similar to the molariform series, with three lobes. Right m 3 shows the characteristic “ Llama buttresses ”. PIMUZ A / V 4192 is a fragment of right hemimandible body with the p 3 – p 4 series (Fig. 4 E 1 – E 2). Te p 3 is transversely compressed and formed by only one lobe; this tooth lacks wear. Te p 4, with slight wear, has a flexid on both, the labial and lingual sides, defining two lobes. Te mesial lobe is mesiodistally elongated, and the distal one is transversely wide. PIMUZ A / V 4195 is the left hemimandible body with the talonid of m 2 and a m 3 (Fig. 4 G 1 – G 2). Te fossae of both molars are closed and the stylids on m 3 are developed. Te hypoconulid is smaller and oval and lack a fossa. PIMUZ A / V 4200 represents a right and left fragment of hemimandibles with teeth. Te right series has the roots of m 1 and complete m 2 – m 3. Te m 3 lacks wear, lacks a hypoconulid, and has a small protostylid, and both fossetids are mesiodistally opened. Te left series has dp 4 – m 2. PIMUZ A / V 4201 is a fragment of the right hemimandible preserving the talonid of the m 2 in advanced wear stage and the entire m 3. No mesial stylids are observed in the m 3, while the hypoconulid is smaller and oval in outline, lacking a fossa. PIMUZ A / V 4179, and PIMUZ A / V 4189, 4127, are isolated m 2, the first is left, and the second and third are right. Teeth have different wear stages, closed fossae, and developed mesial stylids. PIMUZ A / V 4179 shows a “ wear stage 1 ” with its fossetids lingually opened, suggesting this specimen to be of a young camelid (Breyer, 1977). PIMUZ A / V 4255 corresponds to m 1, m 2 and m 3. Teeth do not preserve roots. PIMUZ A / V 4196 is represented by a left permanent p 4 and probably a p 3, m 1 and m 2. Tese teeth are similar to the molariform series previously mentioned in H. paradoxa (PIMUZ A / V 4287; see above). PIMUZ A / V 4257 is a right hemimandible with m 1 – m 3 (Fig. 4 F 1 – F 2). Te teeth have fossae closed, although fossetids on m 3 are erupted and mesiodistally opened. Lingual stylid (protostylid) is presented in all molars and is lingually well developed, while the parastylid is only preserved on m 1 and being more evident in the m 2 (Fig. 4 F 1).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks No diagnostic characters have been observed in the lower deciduous teeth of South American camelids (e. g., Cabrera, 1932, 1935; Rusconi, 1931; Webb, 1974). Te specimens referred above are tentatively attributed to Hemiauchenia cf. H. paradoxa, because they have a similar size and similar dental morphology as shown by H. paradox a from Pleistocene deposits of Argentina and Brazil (Scherer et al., 2007; Vezzosi et al., 2019). cf. Hemiauchenia sp. (Fig. 5 A 1 – E 2). Referred material Isolated molars likely M 1? or M 2? (PIMUZ A / V 4098, 4103, 4180, 4181, 4182). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons Te material is represented by four left (PIMUZ A / V 4103, 4180, 4182), and one right (PIMUZ A / V 4181) likely M 1 or M 2, characterized by different wear stages (Fig. 5 A 1 – E 2). Te mesial lobe is larger than the distal one, with very large stylids (metastyle, parastyle and mesostyle), and with a deeper fossa of the trigon.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks Tese molars have a size similar to those of Hemiauchenia (Cabrera, 1935; Scherer et al., 2007) and with U-shaped lingual lophs differing from those in the teeth of Palaeolama major which are V-shaped (see Scherer et al., 2007; Webb, 1974). According to a study based on North American specimens, the shape of the lophs is a generic difference between Hemiauchenia and Palaeolama (Webb, 1974). Larger samples of South American camelids are needed to test this generic difference among others dental characteristics observed in the upper dentitions. Camelidae indet. (Fig. 5 F 1 – O 2). Referred material Te remains include four lower incisors, fragment of maxilla and right hemimandible, both with dentition (PIMUZ A / V 4253), badly preserved skull, mandible and dentition of a young camelid (PIMUZ A / V 4286), fragment of a mandible and both premaxilla (PIMUZ A / V 4256), 75 isolated molariforms (PIMUZ A / V 4254), and isolated and fragmentary hemimandible, symphysial bone and six incisors and molariform teeth (PIMUZ A / V s / n and no geographic context; see Additional file 1). Postcranial remains include a left eroded metacarpal (PIMUZ A / V 4250), distal end of left tibia with astragalus, navicular and cuboid (PIMUZ A / V 4090), right radius-ulna and right metacarpal, probably from the same individual (PIMUZ A / V 5969), three eroded astragali, a navicular and a podial phalanx (PIMUZ A / V 4208). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons Te left fragment of maxilla of PIMUZ A / V 4253 has the M 1 – M 3 series with the M 1 completely covered by carbonate concretions. Te lower dentition has right i 1 – i 2 and left i 1 – i 2 (this last incisor is isolated) (Fig. 5 G). Te right hemimandible body has the distal root of p 4 and m 1 – m 2 out of their sockets, while m 3 is in eruption (Fig. 5 I 1 – I 2). All molars have similar size to that of a large camelid, although the occlusal surfaces are fractured or covered by carbonates that make them inaccessible for comparisons. Te skull PIMUZ A / V 4286 presents a morphology and dimensions of a small camelid as Lama. However, the carbonates adhered to this specimen make impossible to recognize diagnostic features. Te maxilla and the mandible in this specimen do not present diagnostic elements for a generic assignment. PIMUZ A / V 4254 is represented by numerous upper and lower teeth (N ° 75) of different sizes attributed to Camelidae, and its state of preservation does not allow more accurate determinations. Te left metacarpals III and IV under the number PIMUZ A / V 4250 (Fig. 5 J) are fused to each other, except at the distal end, as is seen in camelids. PIMUZ A / V 4090 is represented by a distal end of left tibia articulated with astragalus, navicular, and cuboid; the covering by carbonates (Fig. 5 M) impedes an assignment beyond the family level. PIMUZ A / V 5969 is a partially damaged right radius-ulna (Fig. 5 L), and right metacarpal (Fig. 5 K). PIMUZ A / V 4208 is represented by three eroded astragali (Fig. 5 N 1 – O 2), a navicular and a podial phalanx. Two of three astragali resemble in size that of a small camelid, such as Lama guanicoe, while the larger has a morphology and size that resembles Hemiauchenia (Scherer et al., 2007). Both navicular and podial phalanx do not allow a more precise determination.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks A specific assignation of the above specimen is not possible due to its poor preservation and / or lack of diagnostic characters. Tayassuidae Palmer, 1897 Tayassu Fischer von Waldheim, 1814 Tayassu pecari (Link, 1795). (Fig. 6 A 1 – A 2). Referred material Left hemimandible fragment with the root of m 2 and m 3 mostly complete (PIMUZ A / V 4188). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 4188 is a fragment of the left hemimandible with the last root of m 2 and a m 3 mostly complete. Te tooth is brachydont and bunodont, preserving three main sharp cusps with slight wear: metaconid mesially, separated by a valley from the hypoconid, and entoconid distally (Fig. 6 A 1). Te molar is broken at the level of the protoconid and consequently we were unable to check the presence of a crenulated cingulid (e. g., Gasparini, 2007). Te first pair of anterior cusps (metaconid and protoconid) are partially broken, although both together are slightly wider than the posterior pair (hypoconid and entoconid), which is well preserved (Fig. 6 A 1). Behind both lobes, there is a third lobe with complex configuration in which four cusps with different size are seen, as in Tayassu pecari (see Gasparini, 2007; Parisi Dutra et al., 2017). Following Gasparini (2007) and Parisi Dutra et al. (2017), PIMUZ A / V 4188 falls in the size range of T. pecari, with a mesio-distal length of 22 mm and a linguolabial width of 12 mm. Tis m 3 is elongated mesiodistally, with subrectangular outline due to the presence of the third cuspidate lobe that forms distally a complex hypoconulid (Frailey & Campbell, 2012).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks Following Gasparini (2007) and Parisi Dutra et al. (2017), the configuration of the m 3 reported here is clearly different from that of Brasilochoerus spp., Parachoerus wagneri, Tayassu tajacu, and Platygonus spp. (with the exception of Platygonus chapadmalensis), because these tayassuids have a simple third lobe (with an unique dominant cusp; see Gasparini, 2007), sometimes accompanied by a pair of smaller cusps (Frailey & Campbell, 2012; Gasparini & Ferrero, 2010). Tayassuidae is among the earliest groups of mammals that entered South America during the GABI (Woodburne, 2010). Teir extensive fossil record is associated with Late Cenozoic deposits in Argentina, Brazil, Uruguay, Bolivia, Colombia, Peru and Venezuela (Gasparini, 2013; Montellano-Ballesteros et al., 2014; Parisi Dutra et al., 2017, and references therein). Te exact moment of its first arrival is controversial, with estimated dates ranging between about 3.7 and 3.1 Ma (see Cione et al., 2007, 2015; Woodburne, 2010). According to the fossil record, the diversity and abundance of tayassuids in South America are greater during the Pleistocene than Pliocene and Holocene (Gasparini, 2013). Moreover, the larger diversity and abundance of fossil species of tayassuids in South America is concentrated in Argentina (Gasparini, 2013), where, according to Gasparini (2007), three genera with twelve species of Tayassuidae were recognized. Peccaries experienced a remarkable decrease in diversity near the Pleistocene – Holocene boundary (Gasparini, 2013), and only two genera (Parachoerus and Tayassu) and three species are living today (Gasparini, 2013; Parisi Dutra et al., 2017). Among these, the white-lipped peccary Tayassu pecari is widely distributed across the Neotropical region, from northern Argentina to southeastern Mexico (Bustos et al., 2019; Gasparini et al., 2014). Despite its large range of distribution and fossil record in South America (Gasparini, 2013; Montellano-Ballesteros et al., 2014), its past occurrence is scarce and restricted to the Middle Pleistocene – Holocene of the Buenos Aires, Corrientes, Misiones, Santa Fe, and Santiago del Estero (Gasparini, 2013; Gasparini et al., 2014). Some morphological features in T. pecari are likely associated with the humid climate conditions and woodland environments that they inhabited (Gasparini et al., 2014). However, Tayassu pecari occupied an extensive geographic range and must have had wide ecological tolerances, making it difficult to predict the habitats where it lived (Parisi Dutra et al., 2017; Bustos et al., 2019). Tayassuidae indet. (Fig. 6 B 1 – B 2). Referred material Left / right? dp 4 with at least two lobes (PIMUZ A / V 5258). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 5258 is a deciduous bunodont and brachydont dp 4, with advanced wear of the occlusal surfaces of their lobes, indicating that the specimen belongs to a young adult individual. Molarization in PIMUZ A / V 5258 is evident as occurs in the deciduous premolars of fossil and living Tayassuidae (Frailey & Campbell, 2012; Gasparini, 2007; Gasparini et al., 2011). Because of wear, it is rather difficult to describe in detail the tooth morphology (e. g., principal and accessory cusps) of PIMUZ A / V 5258.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks A systematic allocation for this isolated tooth (PIMUZ A / V 5258) is doubtful due to its incomplete preservation. Cervidae Goldfuss, 1820 Morenelaphus Carette, 1922 Morenelaphus sp. (Fig. 7 A 1 – A 3). Referred material An incomplete left antler (PIMUZ A / V 4162). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 4162 consists of a long and complex incomplete left antler (Fig. 7 A 1 – A 3). Te preserved portion of antler shows the mean beam, fragmented anteriorly near the second ramification and with a rounded cross-section (Carette, 1922; Kraglievich, 1932). Additionally, the second and third ramifications are directed forward, while the mean beam is backward. Te second and third ramifications form an angle of approximately 45 degrees at the intersection of their axes. Te antler is twisted on its own axis and has longitudinal grooves slightly marked along the external surface, following the torsion of the antler.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks According to Ameghino (1888 b) and Alcaraz (2010), the mean beam in Morenelaphus is clearly curved backwards after the third ramification, as it is observed in PIMUZ A / V 4162. Traditionally, antlers have been used as diagnostic structures for different taxonomic levels within fossil Cervidae from South America (Alcaraz, 2010; Ameghino, 1888 b; Kraglievich, 1932). Some other studies have used other structures for taxonomical purposes (Orcesi et al., 2019; Pêgo, 2014; Vezzosi, 2015; Vezzosi & Chimento, 2021). PIMUZ A / V 4162 is a fragment of antler without any other structure associated, which does not allow an assignment beyond Morenelaphus sp. Morenelaphus is recognized by its long and huge antlers (e. g., Ameghino, 1888 b; Cabrera, 1929 b; Carette, 1922). Two species were described from Pleistocene deposits of Pampean region of Argentina: Morenelaphus brachyceros and Morenelaphus lujanensis. Te systematic distinction of both species is supported solely by the morphology of its antlers (Alcaraz, 2010; Ameghino, 1888 b; Cabrera, 1929 b; Gervais & Ameghino, 1880; Menegaz, 2000); although some cranial and dental features help to differentiate these fossil forms (Chimento et al., 2019; Rotti et al., 2021; Vezzosi & Chimento, 2021; Vezzosi et al., 2020). Te fossil record suggests that both Morenelaphus species belong to different biochronologic intervals within the Pleistocene (Alcaraz, 2010; Cassini et al., 2016). Morenelaphus was considered a typical extinct deer from Pampean lowlands of Argentina, Uruguay, and southern to northern Brazil (Cassini et al., 2016; Chimento et al., 2019; Ferrero et al., 2007; Kraglievich, 1932; Rotti et al., 2021; Ubilla & Martínez, 2016; Vezzosi et al., 2019). Some studies suggest grasses were the most frequent element in the diet of Morenelaphus (Rotti et al., 2018), although Tomassini et al. (2020), suggested more browser feeding preferences. Cervidae indet. (Fig. 7 B 1 – C 2). Referred material Left hemimandible with alveoli of p 2 and p 3 – m 3 series (PIMUZ A / V 4252), and mandible with left p 4 – m 3 series and root of p 2 – p 3, and right dentition with p 3 – m 3 series (PIMUZ A / V 4284). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 4252 is a left hemimandible partially preserved with p 3 – m 3 series and the alveoli of a p 2 (Fig. 7 B 1 – B 3). Teeth do not show an advanced wear stage (Fig. 7 B 1). Te occlusal length of the molar series is 61 mm. PIMUZ A / V 4284 preserves both hemimandibles (Fig. 7 C 1 – C 2). Te left dentition has the p 4 – m 3 series and root of both p 2 – p 3, while the right dentition preserves the p 3 – m 3 series, but its m 1 is lingually broken. Te length of the right m 1 – m 3 series is 51 mm, and the left one is 52 mm. Teeth are bunoselenodont; most of cusps are differentiated, although well-developed cristids are present. Both mandibles are robust with a diastema shorter than that of any living South American deer.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks Te dentition of PIMUZ A / V 4252 and PIMUZ A / V 4284 have a premolar – molar series with six teeth as in Cervidae (Heckeberg, 2020), in contrast to five present in Camelidae (Lynch et al., 2020). Te presence of a short diastema is a morphological character that has been considered diagnostic of Morenelaphus (Alcaraz, 2010; Chimento et al., 2019; Menegaz, 2000; Pêgo, 2014). Pêgo (2014) reported, in the molars of Morenelaphus, a U-shaped morphology in the labial section where the protoconid and hypoconid are present; while living Odocoileini (Blastocerus, Odocoileus, Ozotoceros, Subulo, Pudu, and Hippocamelus) have a V-shaped section. Te U-shape form is observed in the dentitions of both specimens PIMUZ A / V 4252 and PIMUZ A / V 4284 (Fig. 7 B 1, C 1). However, mandibular remains with teeth associated to skulls with dentitions and / or antlers in Morenelaphus are unknown (Vezzosi, 2015; Vezzosi & Chimento, 2021). Moreover, a short diastema is not possible to be recognized in PIMUZ A / V 4252 and PIMUZ A / V 4284, and other specimens of the genus as suggested by Chimento et al. (2019). In fact, the length of the diastema is highly variable during ontogeny in living deer and must be tested in a large comparative framework between South American species. In PIMUZ A / V 4252 and PIMUZ A / V 4284, the dentition, in occlusal view, is subparallel and positioned at the level of the m 2 – m 3 with a more lingual projection in the hemimandible, while in the Camelidae (Hemiauchenia paradoxa, Lama guanicoe, and Palaeolama major) the cheek molars are positioned parallel with a labio-lingual direction to the hemimandible (Lynch et al., 2020; Scherer et al., 2007). Te anterior fossetid opens at the mid-lingual portion of the trigonid in p 4 – m 3 (e. g., Fig. 7 B 1). Tere is no vestige of a back fossetid in m 1 and m 2; however, in m 3 this fossetid opens lingually. Te hypoconulid is large and with a roundedshape. Tere is a circular fossa (Fig. 7 B 1). In South American Camelidae molariforms are smaller with an oval / suboval shape and without a fossa. An anterior cingulid is recognized in p 4, although weakly developed. We do not see an anterior cingulid in m 1, due to preservation and wear stage. Te metaconid is the largest cups of the p 4 trigonid. Te m 3 has the metaconid with pronounced protostylid and parastylid, an uncommon feature among Pleistocene South American Camelidae (Scherer et al., 2007). According to Heckeberg (2020), ectostylids are variably present from one to three in the lower molars of Cervidae. Tose are never high, and are affected by advanced wear in aged individuals. Here an ectostylid in the m 1 is observed (Fig. 7 B 1). We do not rule out that PIMUZ A / V 4252 and PIMUZ A / V 4284 could belong to either Morenelaphus or another American deer, since our comparisons do not allow to offer a more specific determination. It is necessary that these characteristics could be revised and tested in a broader comparative and phylogenetic framework to establish affinities with extant or extinct South American deer. Perissodactyla Owen, 1848 Equidae Gray, 1821 Hippidion Owen, 1869 Hippidion principale (Lund, 1846). Hippidion cf. H. principale (Fig. 8 A 1 – B 2). Referred material A fragmented skull,? right talus articulated with the central tarsal bone, and a left first phalanx from the same individual (PIMUZ A / V 4100). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	description	Description and comparisons PIMUZ A / V 4100 is an incomplete skull preserved only in its ventral side (Fig. 8 A 1). Te premaxilla bears the left I 3, and both maxillae have canines and the complete right and left dental series P 1 – P 4 and M 1 – M 3. With the exception of P 1, premolars and molars are robust and square-like in shape; premolars being larger than molars (Fig. 8 A 2 – A 3). Occlusal length ranges approximately between 45 and 33 mm in premolars, and between 29 and 33 mm in molars. Te right M 1 – M 3 series length is 92 mm, and the left is 94 mm. Te total length of the right series P 1 – M 3 is 216 mm, and the left is 217 mm. Te wear on the premolars and molars is not advanced, allowing a clear observation of the dental morphology, which is characterized by oval to rounded protocone, a hypocone with angular / subtriangular shape, and a more pronounced parastyle than the mesostyle. Te pre / postfossettes are visible only in the M 1. Other cranial / postcranial elements of presumably the same individual include two skull fragments in a poor state of preservation, a? right talus in fragmentary condition and articulated with the central tarsal bone, and a first left phalanx of the third digit of 85 mm in length (Fig. 8 B 1 – B 2).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B36FFC668AAACC1FDF75FE8.taxon	discussion	Remarks According to Alberdi et al., (2005, 2006) the dentition of Hippidion is characterized by an oval to rounded protocone, character that is present in PIMUZ A / V 4100. Hippidion is considered an endemic genus from South America with a biochron spanning from the Pliocene to the Late Pleistocene (Prado & Alberdi, 1996). Tree species have been recognized, (1) Hippidion principale, being the most robust species and the best known from the Argentinian Pampa, and with possible reports from Peru and Ecuador; (2) Hippidion devillei, which is an intermediate size species, with a fossil record throughout the central Andes of Peru and the Argentinian Pampa (although it may have reached as far north as Venezuela, see Labarca et al., 2021); and (3) Hippidion saldiasi, which is the smallest species, restricted to Late Pleistocene deposits from the Patagonian region and some localities further north in Chile (see Alberdi & Prado, 1993; Labarca et al., 2021; Prado & Alberdi, 2017). Hippidion saldiasi is a species named by Roth, 1899 (original nomination Onohippidium saldiasi Roth, 1899). Te differentiation between the Hippidion species combines an analysis of the skull and metapodial characters, with emphasis in the size and proportions of the appendicular bones (Alberdi & Prado, 1993; Alberdi et al., 1995; Prado & Alberdi, 2017). PIMUZ A / V 4100 has dental characters similar to those of H. principale referred from Argentina, Brazil, and Tarija in Bolivia (e. g., Alberdi et al., 2001 b, 2003, 2006; MacFadden, 1997; Prado et al., 2012, 2013). Te dimension of the M 1 – M 3 series and total length of the P 1 – M 3 series in PIMUZ A / V 4100 fit the range of length variability of H. principale. An assignment of PIMUZ A / V 4100 to the largest Hippidion species, H. principale, seems likely.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	description	(Fig. 9 A 1 – E 2).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	materials_examined	Referred material Left M 1 (PIMUZ A / V 4236), left p 4 – m 1 (PIMUZ A / V 4183) and left m 1 (PIMUZ A / V 4212), incomplete right metacarpal (MCIII) with first and second phalanges associated (PIMUZ A / V 4248), and incomplete left metatarsal (MTIII) with articulate tarsal bones (MHNG GEPI V- 3778). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	description	Description and comparisons PIMUZ A / V 4236 is a relatively complete left M 1 (Fig. 9 C 1 – C 2), missing the cementum of the mesial part and with an occlusal length of approximately 30 mm. Te occlusal surface is well preserved and it is possible to observe the pli caballin and a well-defined and triangular protocone that is longer at its distal part than in the mesial part. Te lower left p 4 – m 1 (PIMUZ A / V 4183, Fig. 9 A 1 – A 2) have an occlusal length of 26 mm and 24 mm, respectively. Left m 1 (PIMUZ A / V 4212, Fig. 9 B 1 – B 2) has an occlusal length of 23 mm. Te occlusal surface of the specimens is well-preserved, showing a double knot characterized by a rounded metaconid and a relatively angular metastylid, an elongated ectoflexid, and a protoconid and hypoconid with slightly straight labial edges (see Alberdi et al., 2002; Prado & Alberdi, 2017). Te specimen PIMUZ A / V 4248 is an incomplete right MCIII, missing its proximal part and articulated with first and second phalanges (Fig. 9 E 1 – E 2). Because the bones are preserved in physical connection, we have not been able to take precise measurements, but its maximal length is approximately 83 mm. An evident epiphyseal line shows an incomplete fusion between the diaphysis and epiphysis, which suggests that PIMUZ A / V 4248 could belong to a subadult individual. MHNG GEPI V- 3778 is represented by a left MTIII, missing the left section of the distal epiphysis, for this reason a total length of 240 mm is estimated; all the tarsal bones are still articulated, including the talus and calcaneus (Fig. 9 D 1 – D 2).	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	discussion	Remarks Te dental occlusal pattern and characters present in PIMUZ A / V 4183, 4212, and 4236 (e. g., protocone, metaconid, pli caballin), as described above, can likely be associated more with Equus than Hippidion (see Prado & Alberdi, 2017, and references therein). Te first phalanx articulated to the right MCIII (PIMUZ A / V 4248) is slen- der and more elongated than those present in Hippidion; its maximal length of approximately 83 mm is similar to those reported for Equus (see Prado et al., 2012). Similarly, the rather slender morphology of the left MTIII (MHNG GEPI V- 3778) is characteristic of the genus Equus, with values of a maximal length (240 mm) similar to estimates for E. neogeus (see Prado et al., 2012, table 1). Te taxonomic validity of the South American fossil Equus species have been under debate in the last decades (see Alberdi & Prado, 2004; Prado & Alberdi, 1994, 2017). Hoffstetter (1950) included all different species of Equus from South America in the subgenus Amerhippus, based only in the lack of infundibular marks in the lower incisor surface and consequent loss of surface enamel; nevertheless, the validity and use of Amerhippus have been questioned by Orlando et al. (2008) and Prado & Alberdi (2017). Traditionally five species of Equus were recognized in the fossil record of South America (e. g., Prado & Alberdi, 1994), but Prado & Alberdi (2017) based on both extensive revision of the morphological and morphometric characters of cranial and postcranial elements recognized as valid only three species (1) E. andium (? Middle – Late Pleistocene), (2) E. insulatus (Middle – Late Pleistocene), and (3) E. neogeus (Late Pleistocene). Recently, Machado & Avilla (2019) questioned the diagnosis and taxonomic validity of the three Equus species suggesting the possibility of only a single species of native Equus in South America, namely E. neogeus. We do not rule out that the specimens described herein from the Pampas region could belong to E. neogeus due to their morphology. Equidae indet. (Fig. 9 F 1 – J 2). Referred material A lower symphyseal bone with six incisors (MHNG GEPI V- 3780), right m 1 or m 2 (PIMUZ A / V 4203), and indeterminate lower molar (PIMUZ A / V 4244), two isolated fragmented molariforms and an isolated incisor (PIMUZ A / V 4241), thoracic vertebra (PIMUZ A / V 4132), and second phalange of the III digit (PIMUZ A / V 4242). Geographic data of the specimens are provided in Additional file 1.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	description	Description and comparisons Te lower symphyseal bone with six incisors MHNG GEPI V- 3780 (Fig. 9 G 1 – G 2) shows a dental occlusal surface with advanced wear, likely suggesting an old individual. Tis specimen, together with the other isolated molariforms (PIMUZ A / V 4203, 4241, 4244, Fig. 9 I – J 2), the thoracic vertebra (PIMUZ A / V 4132, Fig. 9 H), a second phalange of the III digit (PIMUZ A / V 4242, Fig. F 1 – F 3), are fragmented or in poor preservation state.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
A12EDA050B2EFFC36B10AE8BFEC75BC8.taxon	discussion	Remarks Te fragmentary and / or poor preserved condition of the above-mentioned specimens makes it difficult to determine diagnostic characters for more precise identifications.	en	Carrillo-Briceño, Jorge D., Vezzosi, Raúl I., Ming, Keesha M., Christen, Zoe M., Mothé, Dimila, Ruiz-Ramoni, Damián, Sánchez-Villagra, Marcelo R. (2023): Nearctic Pleistocene ungulates from the Pampean region (Argentina) in the historical collections of Santiago Roth in Switzerland: an overview. Swiss Journal of Palaeontology 142 (1): 1-26, DOI: 10.1186/s13358-023-00273-7, URL: https://doi.org/10.1186/s13358-023-00273-7
