A new proterochampsid archosauriform from the Middle–Upper Triassic of Southern Brazil

RODRIGO T. MÜLLER

Müller, R.T. 2025. A new proterochampsid archosauriform from the Middle–Upper Triassic of Southern Brazil. Acta Palaeontologica Polonica 70 (1): 7–16.

Proterochampsidae is a clade of carnivorous archosauriforms that lived during the Triassic and is characterized by an elongated rostrum with dorsally oriented external nares, and a unique pes configuration. Although the majority of proterochampsids are found in South America, recent phylogenetic studies suggest a broader geographical distribution for this clade. Most proterochampsids are known from cranial remains; if postcranial elements are known they are frequently poorly preserved. This study describes a new proterochampsid, Retymaijychampsa beckerorum gen. et sp. nov., from the Middle–Late Triassic, based on an almost complete and articulated hindlimb. The holotype was excavated at the Linha Várzea 2 (Becker) Site, located in the municipality of Paraíso do Sul, Rio Grande do Sul, Brazil. The fossils from this locality places it within the Dinodontosaurus Assemblage Zone, which is Ladinian to early Carnian in age according to biostratigraphic investigations. The new taxon is the second proterochampsid described from the Pinheiros-Chiniquá Sequence and represents one of the oldest known members of the clade worldwide. An interesting aspect of R. beckerorum gen. et sp. nov. is its phylogenetic position because it is more closely related to Proterochampsa than to rhadinosuchine proterochampsids. Therefore, the discovery of the new proterochampsid partially fills a long ghost lineage extending from the Middle Triassic to the early Late Triassic. Furthermore, the presence of two proterochampsid species within the Pinheiros-Chiniquá Sequence deposits supports the hypothesis of significant ecomorphological diversity among proterochampsians in Triassic environments.

Key words: Archosauromorpha, Proterochampsia, Proterochampsidae, phylogeny, Carnian, Ladinian, South America, Brazil.

Rodrigo T. Müller [rodrigotmuller@hotmail.com; ORCID: https://orcid.org/0000-0001-8894-9875 ], Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia, Universidade Federal de Santa Maria, São João do Polêsine, RS 598, 97230-000, Brazil.

Received 29 August 2024, accepted 2 November 2024, published online 25 February 2025.

Copyright © 2025 R.T. Müller. This is an open-access article distributed under the terms of the Creative Commons Attribution License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Introduction

The Triassic Period witnessed the emergence and extinction of numerous groups of reptiles (Benton 2016), including the Proterochampsidae (Trotteyn et al. 2013). Although this clade was previously considered endemic to South America (Ezcurra 2010; Trotteyn et al. 2013), recent phylogenetic investigations indicate a broader geographical distribution (Ezcurra and Sues 2021; Paes-Neto et al. 2024). The oldest known proterochampsids have been found in the Ladinian/lower Carnian deposits of Argentina and Brazil (Romer 1971; Arcucci 1990; Hsiou et al. 2002; Trotteyn and Ezcurra 2020; Paes-Neto et al. 2024), whereas the most recent records come from the upper Carnian/lower Norian in the same region (Reig 1959; Barberena 1982). Phylogenetic analyses place Proterochampsidae within Proterochampsia, a clade of archosauriforms that is the sister-group to Archosauria (Ezcurra 2016; Ezcurra and Sues 2021; Müller et al. 2022; Paes-Neto et al. 2024). Because of its affinities, the clade is particularly important for understanding the early evolution of archosaurs. In addition, proterochampsids evolved a relatively diverse array of body plans, with some forms exhibiting putative semi-aquatic adaptations, whereas other were adapted to a terrestrial life style (Reig 1959; Sill 1967; Arcucci et al. 2019; Ezcurra et al. 2021; García Marsa et al. 2023). The diversity within the group includes gracile forms, such as Tropidosuchus romeri Arcucci, 1990, as well as species with flat skulls adorned with protuberances (Reig 1959; Barberena 1982). Proterochampsids are characterized by an elongated skull, particularly a long rostrum, dorsally oriented external nares, and a unique configuration of the pes, which is notably asymmetrical (Trotteyn et al. 2013).

Most proterochampsids are known exclusively from cranial remains (Price 1946; Reig 1959; Barberena 1982; Paes-Neto et al. 2024). In addition, details of certain postcranial structures are often poorly preserved in specimens that include postcranial elements (Trotteyn 2011; Trotteyn and Ezcurra 2014). Therefore, new specimens that preserve such remains are essential for clarifying aspects of the anatomy, biology, and evolution of proterochampsids. Since the pelvic girdle and hindlimb play a crucial role in the phylogenetic context of Archosauria and related groups (Sereno 1991; Nesbitt 2011; Ezcurra 2016), these structures are especially important for investigating the evolution of these groups. The extensive diversity in the structure of the pelvic girdle and hindlimb among early archosaurs and related groups reflects a broad range of postures and ecological adaptations (Hutchinson and Gatesay 2000; Li et al. 2016; Müller et al. 2023; Agnolín et al. 2024). In the present study, a new proterochampsid from the Middle–Upper Triassic of Southern Brazil (Fig. 1) is described. The specimen consists of an almost complete and articulated hindlimb, making it one of the few specimens with these bones preserved from Brazil.

Institutional abbreviations.—CAPPA/UFSM, Centro de Apoio à Pesquisa Paleontológica da Quarta Colônia/Uni­versi­dade Federal de Santa Maria, São João do Polêsine, Rio Grande do Sul, Brazil; MCP, Museu de Ciencias e Tecnología, Pontificia Universidade Catolica, Porto Alegre, Brazil; PVL, Paleontología de Vertebrados, Instituto Miguel Lillo, Tucumán, Argentina; PVSJ, División de Paleontología de Vertebrados del Museo de Ciencias Naturales y Universidad Nacional de San Juan, San Juan, Argentina; UFRGS-PV-T, Triassic Vertebrate Collection of the Museu de Paleontologia da UFRGS “Irajá Damiani Pinto,” Universidade Federal de Rio Grande do Sul, Porto Alegre, Brazil.

Nomenclatural acts.—This published work and the nomenclatural acts it contains have been registered in ZooBank, the online registration system for the International Code of Zoological Nomenclature. The LSID for this publication is: urn:lsid:zoobank.org:pub:FA6231E7-5E62-4221-AB07-E1B1C42BC107.

Material and methods

The phylogenetic affinities of the new proterochampsid were examined using a new data matrix modified from that published by Sengupta et al. (2024). The former data matrix was constructed to investigate a broader context of archosauromorphs (Ezcurra 2016). Therefore, to investigate the affinities of the new taxon within Proterochampsia, a reduced set of operational taxonomic units (OTUs) was selected, which includes all proterochampsians from the previous study. Additionally, Euparkeria capensis, Gnathovorax cabreirai, Buriolestes schultzi, Gracilisuchus stipanicicorum, Presto­suchus chiniquensis, and Diandongosuchus fuyuanensis were selected to compose the outgroup. Following a similar approach to that employed by Langer et al. (2022), only informative characters that vary within the present sample were selected from the original data matrix. A new character based on the ratio between the width of the proximal end of the tibia and the total length of the bone was included (character number 339). The final data matrix is composed of 401 morphological characters and 26 OTUs (see SOM, Supplementary Online Material available at http://app.pan.pl/SOM/app70-Muller_SOM.pdf).

The most parsimonious trees (MPTs) were reconstructed using equally weighted parsimony analysis with the software TNT v. 1.5 (Goloboff and Catalano 2016). Characters 1, 2, 7, 12, 13, 19–23, 30, 31, 34, 36, 41, 44, 46, 52, 57, 58, 62, 76, 90, 111, 116, 118, 126–130, 146, 151, 165, 167, 169, 181, 207, 216, 219, 222, 224, 227, 235, 240, 241, 243, 247, 249, 255, 260, 262, 268, 269, 278, 283, 288, 290, 291, 293, 294, 296, 300, 301, 306, 310, 312, 313, 315, 316, 325, 330, 338, 339, 343, 352, 359, 360, 364, 370, 373, 374, 385, 388, and 389 were set as ordered following previous iterations of the original data matrix (Ezcurra 2016; Ezcurra et al. 2017, 2020; Müller et al. 2023; Sengupta et al. 2024). Euparkeria capensis was used to root the MPTs, which were recovered using the random addition sequence + tree bisection reconnection (TBR), which included 1000 replicates of Wagner trees (with random seed = 0), TBR and branch-swapping (holding 10 trees saved per replicate). Nodes without synapomorphies were collapsed after the search. Decay indices (Bremer support values) and bootstrap values (1000 replicates) were obtained with TNT v. 1.5.

Systematic palaeontology

Archosauromorpha Huene, 1946 (sensu Dilkes 1998)

Archosauriformes Gauthier et al., 1988

Proterochampsidae Sill, 1967 (sensu Trotteyn 2011)

Clade Proterochampsinae nov.

Type genus: Proterochampsa Reig, 1959.

Definition.—Most inclusive clade including Proterochampsa barrionuevoi Reig, 1959, but not Cerritosaurus binsfeldi Price, 1946, nor Rhadinosuchus gracilis Huene, 1938.

Diagnosis.—Ratio between the maximum width of the skull and length of the presacral vertebral column 0.336–0.440; distinct coarse ornamentation on lateral surface of the surangular and angular; in medial view, the area ventral to the internal mandibular fenestra showing a larger contribution from the angular bone compared to the prearticular, or both bones contribute equally; prearticular with ventral margin posterior to its contact with the splenial straight or ventrally curved on the anterior half of the bone in medial or lateral view; and presence of ventral keel on ninth presacral vertebral centrum.

Genus Retymaijychampsa nov.

ZooBank LSID: urn:lsid:zoobank.org:act:99025E25-552E-47C4-BEC4- C2FCCCEADEEE

Type species: Retymaijychampsa beckerorum gen et sp. nov., monotypic, see below.

Etymology: The combination of Guarani retyma, leg and ijy, strong with Greek champsa, crocodile; referring to the robust constitution of the animal’s hindlimb.

Diagnosis.—Same as for the only known species.

Retymaijychampsa beckerorum sp. nov.

Fig. 3.

ZooBank LSID: urn:lsid:zoobank.org:act:80A4B7E7-6C18-4A81-B668- B623A9D416A4

Etymology: In honor of the family Becker, the owners of the property were the Linha Várzea 2 site is located.

Holotype: CAPPA/UFSM 0430, a complete and articulate right hindlimb.

Type locality: Linha Várzea 2 (= Becker) site (29°44′03″ S, 53°09′07″ W), Paraíso do Sul, Rio Grande do Sul, Brazil (Fig. 1).

Type horizon: Santa Maria Formation (Schultz et al. 2020); Pinheiros-­Chiniquá Sequence (Horn et al. 2014) of the Santa Maria Supersequence (Zerfass et al. 2003), Paraná Basin. This third-order sequence is associated with the Dinodontosaurus Assemblage Zone, which is Ladinian to early Carnian in age (Ezcurra et al. 2017; Schultz et al. 2020; Novas et al. 2021; Müller and Garcia 2022).

Material.— Holotype only.

Diagnosis.—Retymaijychampsa beckerorum gen. et sp. nov. differs from all other known proterochampsids with comparable skeletal material based on the following local autapomorphies: absence of an extensor fossa on the anterior surface of the distal portion of the femur, resulting in a straight anterior margin in distal view; fibular condyle of the femur projects more ventrally than tibial condyle, forming an uneven distal surface in anterior view; and markedly robust tibia, with a ratio of 0.37 between the maximum width of the proximal end and the total length of the bone.

Description.—Although the femur lacks the proximal portion, it cleary had a sigmoid shape (Fig. 3A1). The preserved segment of the shaft includes the distal half of the fourth trochanter, which forms an elongated ridge (Fig. 3A6). The distal portion of the trochanter merges smoothly with the shaft. Whereas the femur is not completely preserved, it is evident that the fourth trochanter is distally elongated, similar to the condition seen in most proterochampsids (Trotteyn et al. 2013). Conversely, the fourth trochanter of Stenoscelida aurantiacus Müller et al., 2022 (CAPPA/UFSM 0293; Müller et al. 2022) and Tropidosuchus romeri Arcucci, 1990 (PVL 4601; Arcucci 1990) is short. The distal portion of the femur expands relative to the shaft and is arched posteriorly. The popliteal fossa is not elongated. Unlike other proterochampsids (Trotteyn 2011; Trotteyn and Ezcurra 2020; Müller et al. 2022; Paes-Neto et al. 2024), this specimen lacks an extensor fossa on the anterior surface of the distal portion of the femur, resulting in a straight anterior margin in distal view (Fig. 3A4, A8). In addition, compared to other proterochampsids, the fibular condyle projects more ventrally than the tibial condyle, forming an uneven distal surface in anterior view. The tibiofibular crest is not strongly expanded and there are no distinguishing features between the lateral surface of the tibiofibular crest and the lateral condyle.

The complete tibia (Table 1) is notably robust, with a ratio of 0.37 between the maximum width of the proximal end and the total length of the bone. For comparison, the ratio for the holotype of Stenoscelida aurantiacus (CAPPA/UFSM 0293) is 0.25 and for the holotype of Kuruxuchampsa dornellesi Paes-Neto et al., 2024 (UFRGS-PV-0877-T) is 0.26. In lateral/medial view, the proximal portion of the tibia is expanded both anteriorly and posteriorly relative to the shaft (Fig. 3A5). The anterior projection comprises the cnemial crest, which tapers to a point and is straight (Fig. 3A6). The posterior projection is the medial condyle, which is positioned further posteriorly relative to the lateral condyle. The proximal articular surface is flat. The shaft of the tibia is straight and expands distally, with the expansion predominantly oriented anteroposteriorly. This condition differs the specimen from Tropidosuchus romeri (PVL 4601; Arcucci 1990), in which the distal end of the tibia is not expanded. The posterior margin of the distal end of the tibia of CAPPA/UFSM 0430 is gently concave (Fig. 3A7).

The fibula is slender, with a shaft that has approximately half the transverse width of the tibial shaft (Fig. 3A6). The fibula is slightly shorter than the tibia (Table 1). The proximal end is expanded posteriorly relative to the shaft and is compressed transversely (Fig. 3A6). The shaft is straight along its length, differing from the arched shaft of the fibula in most pseudosuchians (Nesbitt 2011; Ezcurra 2016). The width of the shaft remains consistent along the entire length of the fibula, whereas in Stenoscelida aurantiacus (CAPPA/UFSM 0293; Müller et al. 2022) the proximal half of the shaft is wider. There is no tubercle or ridge for the attachment of the iliofibularis muscle, such as in Proterochampsa barrionuevoi Reig, 1959 (PVSJ 606; Trotteyn et al. 2013). The distal end expands relative to the shaft, and the distal articular surface is flat.

The astragalus is transversely expanded (Fig. 3A7). The dorsal margin of its medial surface is concave, while its ventral surface of the bone is convex anteroposteriorly. There is no anterior expansion at the anteromedial corner. The posterior margin lacks a dorsal process. The calcaneum is lateromedially shorter than the astragalus (Fig. 3A6, A7). The facet for the fibula is oriented dorsomedially. The calcaneal tuber is well-developed and perpendicular to the main body of the calcaneum (Fig. 3A6). There is a depression between the main body of the bone and the posterior surface of the calcaneal tuber (Fig. 3A6, A7).

The configuration of the metatarsals is consistent with that in other proterochampsids (Table 1): metatarsal I is short; metatarsal II is slightly longer than metatarsal I and the stoutest of the elements; metatarsal III is longer than metatarsal II and more slender; metatarsal IV is quite slender and as long as metatarsal III; and metatarsal V is reduced and tapers distally. Pedal digit I includes two phalanges (Fig. 3A5). The specimen differs from Tropidosuchus romeri (PVL 4601; Arcucci 1990) and Stenoscelida aurantiacus (CAPPA/UFSM 0293; Müller et al. 2022) in that both of the latter taxa have a shorter digit I. Whereas pedal digit II is longer than digit I, it is shorter than digit III (Fig. 3A6). Digit IV preserves one phalanx, which is quite slender (Fig. 2A5, A6). As this phalanx is not an ungual bone, the total number of phalanges in this digit remains uncertain. There are no phalanges in the digit V. This condition is shared with other proterochampsids, whereas a putative vestigial phalanx has been reported for Stenoscelida aurantiacus (CAPPA/UFSM 0293; Müller et al. 2022).

Stratigraphic and geographic range.—Type locality and horizon only.

Phylogenetic analysis

The phylogenetic analysis recovered a single most parsimonious tree (Fig. 4) of 914 steps each, with a consistency index of 0.521 and a retention index of 0.557. Retymaijychampsa beckerorum gen. et sp. nov. is found in a trichotomy with both species of Proterochampsa, based on the elongated fourth trochanter of the femur (ch. 329: 0→1) and the ratio between the maximum width of the proximal end and the total length of the tibia (ch. 339: 2→3). Sphodrosaurus pennsylvanicus is the sister taxon to the node comprising R. beckerorum gen. et sp. nov. plus both species of Proterochampsa. The clade comprising these four OTUs is named here Proterochampsinae and is supported by five synapomorphies: ratio between the maximum width of the skull and length of the presacral vertebral column ranging from 0.336 to 0.440 (ch. 12: 1→3); distinct coarse ornamentation on lateral surface of the surangular and angular (ch. 187: 0→1); in medial view, the area ventral to the internal mandibular fenestra shows a larger contribution from the angular bone compared to the prearticular, or both bones contribute equally (ch. 188: 0→1); prearticular with ventral margin posterior to its contact with the splenial straight or ventrally curved on the anterior half of the bone in medial or lateral view (ch. 189: 1→0); and presence of ventral keel on the centrum of the ninth presacral vertebra (ch. 231: 0→1). Stenoscelida aurantiacus is recovered as the sister taxon to Proterochampsidae. The inner composition of Proterochampsidae and Doswelliidae follows previous analyses of the original data matrix (Paes-Neto et al. 2024).

An interesting aspect to note is that, prior to the advent of computational phylogenetic analyses, Bonaparte (1971) divided proterochampsians into two main families: “Proterochampsidae” and “Cerritosauridae”. Although far fewer proterochampsian species were known at the time, this subdivision closely aligns with the results obtained in the present analysis.

Discussion

Although most typical traits of proterochampsids concern cranial bones (Ezcurra 2016), Retymaijychampsa becke­rorum gen. et sp. nov. is confidently assigned to Protero­champsidae based on the configuration of the pes, which has a stout metatarsal II combined with a rather slender metatarsal IV (e.g., Trotteyn et al. 2013). On the other hand, the new proterochampsid had a unique set of traits that are associated with the robustness of the hindlimb and the shape of the distal end of the femur. The significance of these features is uncertain. Perhaps R. beckerorum gen. et sp. nov. had a posture or mode of locomotion distinct from other proterochampsids. In addition, the holotype (CAPPA/UFSM 0430) represents a small individual. In proterochampsids, the tibia length ranges from approximately 75% (Proterochampsa barrionuevoi; Trotteyn 2011) to 100% (Tropidosuchus romeri; Arcucci 1990) of the total femur length. Based on the tibia length of 70.5 mm and the cited tibia-to-femur ratios in proterochampsids, the estimated femoral length of CAPPA/UFSM 0430 should range between 70.5 mm and approximately 94 mm. According to these values, the length of the skull of CAPPA/UFSM 0430 is estimated between 79.8 to 126.4 mm based on the regression calculated by Müller et al. (2022). Therefore, the holotype of R. beckerorum gen. et sp. nov. was a small-sized proterochampsid when compared to most members of the clade. For comparison, the skull of the holotype of Pinheirochampsa rodriguesi is 276.5 mm in length (Paes-Neto et al. 2024), that of the holotype of Gualosuchus reigi is 330 mm (Romer 1971), and the skulls of some specimens of Proterochampsa barrionuevoi reached approximately 500 mm (Dilkes and Arcucci 2012). Nevertheless, there are some small proterochampsids, such as Tropidosuchus romeri, whose skull was approximately 76 mm in length (Arcucci 1990). Despite the reduced size, a histological investigation suggested that a specimen of Tropidosuchus romeri (PVL 4606) reached sexual and skeletal maturity, though somatic maturity could not be inferred (García Marsa et al. 2023). Therefore, whereas small proterochampsids are present in the fossil record, further investigations and/or specimens are necessary to determine whether CAPPA/UFSM 0430 represents a skeletally immature individual.

Retymaijychampsa beckerorum gen. et sp. nov. repre­sents the second proterochampsid from the Pinheiros-Chini­quá Sequence. The other species, Pinheirochampsa rodri­guesi, is known solely from cranial remains (Paes-Neto et al. 2024). Therefore, a direct comparison between CAPPA/UFSM 0430 and specimens of Pinheirochampsa rodriguesi is not feasible. Even the size difference between CAPPA/UFSM 0430 and specimens of Pinheirochampsa rodriguesi are an ambiguous difference because the development degree of CAPPA/UFSM 0430 is uncertain. On the other hand, both species belong to different clades according to the phylogenetic analysis performed here. Retymaijychampsa beckerorum gen. et sp. nov. nests within Proterochampsinae, whereas Pinheirochampsa rodriguesi is a derived member of Rhadino­suchinae. Therefore, although more complete specimens are needed to further investigate this taxonomic issue, the cladistic data supports the presence of two phylogenetically distinct proterochampsids in the Pinheiros-Chiniquá Sequence. Actually, the co-occurrence of different proterochampsian species is common in South American deposits (Fig. 5). For instance, in the Massetognathus–Chanaresuchus Assemblage Zone of the Argentinean Chañares Formation there are three coeval species (Ezcurra et al. 2021). In the Hyperodapedon Assemblage Zone of the Brazilian Candelária Sequence, there are four species distributed across two sub-zones (Müller et al. 2022). The co-occurrence of R. beckerorum gen. et sp. nov. and Pinheirochampsa rodriguesi reinforces an ecological model in which proterochampsians were relatively diverse in Middle to early Late Triassic environments (Fig. 6). Moreover, if the size differences between the two species are not due to ontogenetic variation, it is plausible that these species occupied distinct niches, especially if the unique hindlimb morphology of R. beckerorum gen. et sp. nov. is associated with a distinct locomotor strategy compared to other proterochampsians. In fact, archosauriforms evolved a broad range of postures and locomotor strategies during the Triassic (Agnolín et al. 2024).

Another interesting aspect of the discovery of R. beckerorum gen. et sp. nov. concerns its phylogenetic position. So far, there have been no records of Ladinian to early Carnian proterochampsids more closely related to Proterochampsa (i.e., Proterochampsinae) than to rhadinosuchines, resulting in a ghost lineage extending from the Middle to early Late Triassic (Ezcurra and Sues 2021; Paes-Neto et al. 2024). Retymaijychampsa beckerorum gen. et sp. nov. partially fills this gap and represents the oldest known proterochampsine proterochampsid worldwide. It highlights the phylogenetic importance of postcranial remains in order to further explore the evolutionary history of these archosauriforms. In addition, the composition of Proterochampsinae including three South American taxa along with the North American Sphodrosau­rus pennsylvanicus (Paes-Neto et al. 2024; here), suggests a wide geographical distribution of this clade. These affinities add to the growing number of Triassic tetrapod taxa shared between deposits in South America and North America (Irmis et al. 2007; Martínez et al. 2016; Novas et al. 2021; Ezcurra and Sues 2022; Fitch et al. 2023; Müller et al. 2023).

Conclusions

Retymaijychampsa beckerorum gen. et sp. nov. represents the second pro­tero­champsid from the Pinheiros-Chiniquá Sequence (Ladi­nian to upper Carnian) of Brazil and comprises one of the oldest proterochampsids worldwide. It has a diagnostic set of hindlimb traits and is phylogenetically close to Proterochampsa, partially filling a ghost lineage of proterochampids more closely related to Proterochampsa than to Rhadinosuchinae. Finally, the co-occurrence of R. beckero­rum gen. et sp. nov. and Pinheirochampsa rod­ri­guesi provides further support for the idea of high ecomorphological diversity among proterochampsians in Middle to early Late Triassic environments.

Acknowledgements

I thank Pedro Lucas Porcela Aurélio (Cachoeira do Sul, Brazil) for the discovery of the material described here, Becker family (Paraíso do Sul, Brazil) for kindly allowing the palaeontological prospection and fieldwork at their property, Federico Agnolín (Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina) and Hans-Dieter Sues (Smithsonian Institution, Washington DC, USA) for their valuable comments and suggestions, Caio Fantini (Guarulhos, Brazil) for the artistic representation of the new taxon, and Dilson Vargas Peixoto (Santa Maria, Brazil) for the linguistic assistance in the creation of the new taxon’s name. I also thank the Willi Hennig Society, for making the TNT software freely available. This work was carried out with aid of the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 404095/2021-6, 303034/2022-0, and 406902/2022-4).

Editor: Daniel Barta.

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Acta Palaeontol. Pol. 70 (1): 7–16, 2025

https://doi.org/10.4202/app.01204.2024