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Neoaetosauroides engaeus Bonaparte. Reconstrucci?n del esqueleto y coraza./ Neoaetosauroides engaeus Bonaparte. Restoration of the skeleton and caparace.  

Neoaetosauroides engaeus Bonaparte. Reconstrucci?n del esqueleto y coraza./ Neoaetosauroides engaeus Bonaparte. Restoration of the skeleton and caparace.  

Citations

... The drawing provided by Walker (1961) is still the leading representation of the pelvic girdle of Aetosauria. The pictures or drawings of the ilium of Aetosauroides scagliai , S. robertsoni (Walker, 1961), Polesinesuchus aurelioi juvenile (Roberto-da-Silva et al., 2014), Neoaetosauroides engaeus (Desojo and Báez, 2005), Calyptosuchus wellesi (Case, 1922;Long and Murry, 1995), Longosuchus meadei (distorted), Lucasuchus hunti, Desmatosuchus 'haplocerus', Typothorax coccinarum (damaged; Long and Murry, 1995), Desmatosuchus spurensis (distorted; Parker, 2008) and Aetosaurus ferratus (Schoch, 2007) are compared with the ilia of Stagonolepis from Krasiejów (UOPB01141, UOPB00148, UOPB00149 and UOPB00150). The ilium DMNH 9938, mentioned by Long and Murry (1995) as belonging to Paratypothorax, is not considered further because of the uncertainty about its status. ...
... Most ilia of aetosaurs have this morphology, but those of Aetosaurus ferratus (Schoch, 2007, fig. 11), a juvenile (Schoch and Desojo, 2016), Neoaetosauroides engaeus (Desojo and Báez, 2005, fig. 2) and Desmatosuchus spurensis (Parker, 2008, fig. ...
... A large part of the pedestal is the acetabulum, dorsally bordered by the supracetabular crest. The acetabulum is shallow in Polesinesuchus aurelioi (Roberto-da-Silva et al., 2014) and deep in Neoaetosauroides engaeus (Desojo and Báez, 2005), Scutarx deltatylus (Parker, 2016b) and Desmatosuchus smalli (Small, 1985). Case (1922) described the acetabulum of Desmatosuchus 'haplocerus' (UMMP7322) as very deep. ...
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In recent years, the Upper Triassic deposits at Krasiejów (south-west Poland) have yielded several tetrapod taxa, both aquatic and terrestrial. Stagonolepis olenkae is one of the terrestrial vertebrates recovered there; a quadrupedal, armoured aetosaur, which belonged to the crocodile-line archosaurs with a characteristic shovel-shaped snout. Several previous studies (osteological, histological and taphonomic) have attempted to understand the mode of life, growth pattern and possible dimorphism of this species and on this basis, to interpret palaeoecological, palaeoclimatic and stratigraphical implications. So far, the pelvic girdle of S. olenkae from Krasiejów remained undescribed. Here, the authors record stagonolepid ilia and pubes and a single ischium from collections housed at the University of Opole, and compare these with the pelvic girdles of other aetosaurian taxa. These well-preserved bones have a typical aetosaurian general outline, but also show some peculiar features. For instance, the preacetabular blade of the ilium is short and flattened and does not exceed the pubic peduncle; several small foramina occur dorsally of the supracetabular crest; the number of pubic foramina is two and the pubic symphysis is less than half the length of the pubis. The material is similar to previously known Stagonolepis robertsoni from the Elgin area, except for the length of the symphysis. The bones presented here differ between each other in thickness, morphology of the preacetabular blade or attachment of sacral ribs, which may be connected with sexual dimorphism. The pelvic girdle of most aetosaurs is not well known. This is unfortunate, because it is an important element in the study of the evolution of the pelvic girdle and in phylogenetic analyses. Thus, the ilia, pubes and ischium of the present study are valuable examples that may contribute to the discussion of the ontogeny and sexual dimorphism in Stagonolepis, as well as to our general knowledge of the Aetosauria.
... Dentro de la diversa fauna hallada en Los Colorados se han encontrado restos óseos que corresponden a varios grupos del clado Pseudosuchia y a dos grupos del clado Dinosauria (Theropoda y Sauropodomorpha) (Arcucci et al., 2004;Abdala et al., 2017). Riojasuchus tenuisceps (Ornithosuchidae) y Neoaetosauroides engaeus (Aetosauria) son dos pseudosuquios cuya anatomía es bien conocida y que a pesar de haber alcanzado tamaños considerablemente mayores a PULR-V126, en base a las dimensiones de sus huesos preservados, también son distintos por tener centros vertebrales con "forma de carretel" muy marcada, particularmente en las vértebras caudales, y ausencia de láminas accesoria entre las apófisis y entre ellas y los centros vertebrales (Desojo & Báez, 2005;Nesbitt, 2011;von Baczko et al., 2020). Otro elemento postcraneano comparable entre PULR-V126 y esas dos especies es el fémur, particularmente el extremo proximal de Riojasuchus tenuisceps y Neoaetosauroides engaeus posee los tres tubérculos (anterolateral, posteromedial y anteromedial) que en general se observan en la mayoría de los arcosaurios (Nesbitt, 2011), pero además presentan una disparidad de tamaños siendo el tubérculo posteromedial el más grande de los tres (von Baczko et al., 2020). ...
Article
In the present contribution we study a fragmentary specimen of Crocodylomorpha recovered from outcrops of the Los Colorados Formation (Late Triassic) of the Ischigualasto-Villa Unión Basin. The material (PULR-V126) was deposited in the Museo de Ciencias Naturales of the Universidad Nacional de La Rioja, without any other data of origin or collector. The specimen consists of scarce postcranial remains, which include associated dorsal and caudal vertebrae, the proximal end of the humerus, and the proximal and distal ends of the femur, among other elements. The detailed study of the anatomy of the specimen was performed and a single autapomorphy was recognized: transverse processes of its middle/posterior dorsal vertebrae have a strong dorsolateral orientation. However, given the scarce remains of PULR-V126, we consider that this trait is not enough to support the creation of a new taxon based on this material. The specimen was included in a previously published morphological phylogenetic character matrix, in which both the sampling of taxa (2) and postcranial characters (1) were increased. Specimen PULR-V126 is recovered in several positions as a non-crocodyliform crocodylomorph in the different most parsimonious trees. This is caused by the lack of preservation informative characters in PULR-V126 that precluded the evaluation of its precise phylogenetic relationships within other crocodylomorphs © 2022. Revista del Museo Argentino de Ciencias Naturales, Nueva Serie.All Rights Reserved.
... Dentro de la diversa fauna hallada en Los Colorados se han encontrado restos óseos que corresponden a varios grupos del clado Pseudosuchia y a dos grupos del clado Dinosauria (Theropoda y Sauropodomorpha) (Arcucci et al., 2004;Abdala et al., 2017). Riojasuchus tenuisceps (Ornithosuchidae) y Neoaetosauroides engaeus (Aetosauria) son dos pseudosuquios cuya anatomía es bien conocida y que a pesar de haber alcanzado tamaños considerablemente mayores a PULR-V126, en base a las dimensiones de sus huesos preservados, también son distintos por tener centros vertebrales con "forma de carretel" muy marcada, particularmente en las vértebras caudales, y ausencia de láminas accesoria entre las apófisis y entre ellas y los centros vertebrales (Desojo & Báez, 2005;Nesbitt, 2011;von Baczko et al., 2020). Otro elemento postcraneano comparable entre PULR-V126 y esas dos especies es el fémur, particularmente el extremo proximal de Riojasuchus tenuisceps y Neoaetosauroides engaeus posee los tres tubérculos (anterolateral, posteromedial y anteromedial) que en general se observan en la mayoría de los arcosaurios (Nesbitt, 2011), pero además presentan una disparidad de tamaños siendo el tubérculo posteromedial el más grande de los tres (von Baczko et al., 2020). ...
... There is evidence of at least two phalanges and, possibly, an ungual for III as well. The phalangeal formula for the first three digits (2-3-3+) therefore matches other aetosaurs where the foot is known (most considered 2-3-4-5-x, where x ranges from 2-4) (Walker, 1961;Desojo & Báez, 2005;Schoch, 2007;Heckert et al., 2010;Lucas & Heckert, 2011). The more distal phalanges are always considerably shorter than the next most proximal element, usually by a factor of 50%, except for the unguals, both of which are approximately 25 mm long in side view (with articular facet oriented vertically) but 30-35 mm long along the curve of the claw. ...
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Aetosaurs are an early-diverging clade of “crocodile-line” archosaurs whose oldest records come from Argentina and Brazil. Articulated skeletons of aetosaurs are rare, but offer insight into their paleobiology. We describe here an incomplete, articulated posterior skeleton of an aetosaur from the Upper Triassic Ischigualasto Formation of San Juan Province, Argentina. It resembles Aetosauroides, the only aetosaur genus currently recognized from the Ischigualasto Formation, but lacks apomorphies that would allow us to assign it to that taxon, appears to be more robust than the holotype of A. scagliai, and preserves a different tail morphology. We identify the specimen as a basal aetosaur in part because the few exposed dorsal and lateral osteoderms have a typical ornamentation of radially distributed pits, grooves, and ridges emanating from a “center of ossification.” Although the specimen is incomplete and exposed primarily in ventral view from the sacrum posteriorly, it preserves many anatomical features not often preserved in aetosaurs, including extensive appendicular armor and a well- preserved caudal ventral carapace. The latter apparently consists of only two columns of ventral osteoderms, and preserves a large cloacal vent proximally. Posteriorly, the ventral paramedian osteoderms fuse to form a single element, something that has not previously been demonstrated in aetosaurs. The arrangement of osteoderms around the vent is distinct from that seen in A. scagliai. The ventral caudal osteoderms differ from many other aetosaurs in that they do not transition from wider than long to longer than wide, indicating that the specimen had a relatively abbreviated tail.
... Aetosauroides ferratus Fraas, 1877 (body length ca. 1 m) to larger species such as Desmatosuchus spurensis Case, 1920 (body length ca. 6 m) (Sawin, 1947;Walker, 1961;Desojo, 2003;Desojo & Báez, 2005;Schoch, 2007;Parker, 2008;Heckert et al., 2010;Desojo et al., 2013;Taborda et al., 2013). ...
... Aetosaurs were quadrupedal armored animals with a semi-erect posture (Parrish, 1986;Desojo & Báez, 2005;Padian et al., 2010). They have a relatively small head that is approximately 12% of the total length of the body (Taborda, 2011). ...
Article
Aetosaurs are an archosaur group with a worldwide distribution during the Late Triassic. They were quadrupedal amniotes, had small heads relative to their body size, and had a long tail. Characterized by a dorsal and ventral carapace formed by ornamented and articulated osteoderms, aetosaur feeding ecology is poorly understood. Although aetosaurs are historically considered as the only herbivore among early pseudosuchian archosaurs, some authors have proposed omnivorous and/or scavengers habits for this group. Neoaetosauroides engaeus Bonaparte, 1969, an aetosaur from Late Triassic known from three relatively well preserved skulls (from the Los Colorados Formation, La Rioja, Argentina), is an excellent taxon to make biomechanics models of feeding to decipher the feeding ecology of this clade. We applied the Finite Element Method (FEM) for estimating the bite force and evaluated the structural response of the skull at different positions during the food processing. Our results show that the skull of N. engaeus generated a bite force of 3.6kN (magnitude comparable with the measurement made in Alligator mississippiensis) and could resist lateral and longitudinal forces during feeding. This indicates that these animals were capable of hunting of small living prey with their jaws (e.g. cynodonts), and/or drag carcasses of larger sizes (e.g. dicynodont). These results support possible zoophagy or omnivory for N. engaeus, and thus expanding the potential ecological roles of aetosaurs.
... In Aetosaurus ferratus (SMNS 5770 S-22;Schoch, 2007: fig. 11b), Neoaetosauroides engaeus (PVL 3525; Desojo and Báez, 2005: fig. 2c), and Calyptosuchus wellesi (UMMP 13950; Parker, 2018a), this distance and angle is smaller, more similar to Revueltosaurus callenderi (e.g., PEFO 34561) and other non-aetosaurs (e.g., the erpetosuchid Tarjadia ruthae; CRILAR-Pv 478; Ezcurra et al., 2017:fig. ...
Article
Acaenasuchus geoffreyi is a diminutive armored archosaur from the Upper Triassic Chinle Formation of northern Arizona, U.S.A., with uncertain evolutionary relationships and skeletal maturity. Known only from osteoderms, the taxon has been considered a valid taxon of aetosaur, juvenile specimens synonymous with the aetosaur Desmatosuchus spurensis, or a non-aetosaurian pseudosuchian archosaur. Here, we describe new fossils of Acaenasuchus geoffreyi that represent cranial, vertebral, and appendicular elements as well as previously unknown variations in the dorsal carapace and ventral shield. The skull bones are ornamented with the same anastomosing complex of ridges and grooves found on the paramedian and lateral osteoderms, and the appendicular skeleton resembles that of Revueltosaurus callenderi, Euscolosuchus olseni, aetosaurs, and other armored archosaurs such as erpetosuchids. Histology of osteoderms from the hypodigm of Acaenasuchus geoffreyi shows multiple growth lines, laminar tissue, and low vascularity, evidence that the individuals were close to skeletal maturity and not young juveniles. A revised phylogenetic analysis of early archosaurs recovers Acaenasuchus geoffreyi and Euscolosuchus olseni as sister taxa and members of a new clade that is the sister taxon of Aetosauria. This new phylogeny depicts a broader distribution of osteoderm character states previously thought to only occur in aetosaurs, demonstrating the danger of using only armor character states in aetosaur taxonomy and phylogeny. Acaenasuchus geoffreyi is also a good example of how new fossils can stabilize 'wild card' taxa in phylogenetic analyses and contributes to our understanding of the evolution of the aetosaur carapace.
... Aetosaurs are heavily armored, quadrupedal basal archosaurs cladistically nested within Pseudosuchia, the crocodile lineage of archosaurs (e.g., Brusatte et al., 2010;Nesbitt, 2011;Desojo, Ezcurra & Kischlat, 2012;Desojo et al., 2013). They are medium to large sized animals (one to six m long) with semi-erect to erect gait (Parrish, 1986;Desojo & Báez, 2005;Desojo & Vizcaíno, 2009;Heckert et al., 2010;Padian, Li & Pchelnikova, 2010;Desojo et al., 2013). Their most characteristic feature is the suit of dermal armor composed of rectangular, plate-like osteoderms, which cover the dorsal and partially the lateral surfaces of their bodies, and in more heavily armored species also the belly, ventral surfaces of the tail and the limbs (e.g., Walker, 1961;Heckert & Lucas, 2000;Desojo et al., 2013). ...
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Aetosaurs are armored basal archosaurs that played a significant role in land ecosystems during the Late Triassic (237-201 Ma). The polish species Stagonolepis olenkae Sulej, 2010 described from the Krasiejów locality (southern Poland) is one of the oldest known representatives of the group. Abundant and well-preserved material, including partially articulated specimens, allows a detailed description of the forelimbs in this species. The forelimbs of S. olenkae are the most similar to that of large aetosaurs like Desmatosuchus smalli, Desmatosuchus spurensis, Longosuchus meadei, Typothorax coccinarum or Stagonolepis robertsoni. Several characters recognized in the forelimbs of S. olenkae suggest its adaptation for scratch-digging. The most salient of these features are: short forearm, carpus, and hands, with the radius shorter than the humerus, carpus and manus shorter than the radius (excluding terminal phalanges); a prominent deltopectoral crest that extends distally on the humerus and a wide prominent entepicondyle, a long olecranon process with well-marked attachment of triceps muscle; hooked, laterally compressed, claw-like terminal phalanges with ornamentation of small pits (indicative of well-developed keratin sheaths). S. olenkae might have used its robust forelimbs to break through the compacted soil with its claws and proceed to dig in search of food in softened substrate with the shovel-like expansion at the tip of its snout. The entire forelimb of S. olenkae is covered by osteoderms, including the dorsal surface of the hand, which is unusual among aetosaurs and have not been noted for any species up to date. Subjects Paleontology, Zoology.
... Among aetosaurs, the number of sacral vertebrae may be variable. Most described aetosaurs possess only two unfused sacral vertebrae (Mehl, 1915;Case, 1929Case, , 1932Walker, 1964;Lucas et al. 2002;Desojo & B aez, 2005;Parker, 2008); however, the sacrum of Desmatosuchus spurensis has been variously interpreted as possessing two primordial sacrals and a dorsosacral (Small, 1985;Nesbitt, 2011), or, conversely, only two primordial sacrals, with the last presacral vertebra fully co-ossified to the sacrum but lacking articulation with the ilium (Parker, 2008). Here, we follow Small (1985) and Nesbitt (2011) in considering the first sacral of Desmatosuchus spurensis a trunk vertebra that has been incorporated into the sacrum (= a dorsosacral). ...
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The sacrum – consisting of those vertebrae that articulate with the ilia – is the exclusive skeletal connection between the hindlimbs and axial skeleton in tetrapods. Therefore, the morphology of this portion of the vertebral column plays a major role in the evolution of terrestrial locomotion. Whereas most extant reptiles only possess the two plesiomorphic sacral vertebrae, additional vertebrae have been incorporated into the sacrum multiple times independently among early-diverging archosaurian (crocodylians + birds) clades. Phytosauria was a diverse, abundant, and cosmopolitan clade of archosauriforms throughout the Late Triassic, but postcrania of this clade are rarely described and few species-level taxonomic placements of phytosaurian postcranial material are available, potentially hampering knowledge of morphological disparity in the postcranial skeleton among phytosaurs. Here, we describe the sacrum of Smilosuchus adamanensis, a phytosaur recovered from the Upper Triassic Chinle Formation of Arizona. This sacrum consists of the two primordial sacral vertebrae, but has a vertebra incorporated from the trunk into the sacrum (= a dorsosacral) and is therefore the first Late Triassic phytosaur and one of the first non-archosaurian archosauromorphs to be described with more than two sacral vertebrae. Our interpretation of this element as a dorsosacral is justified by the lateral extent of the dorsosacral ribs, clear surfaces of articulation between the distal ends of the dorsosacral ribs and the first primordial sacral ribs, and the scar on the medial surface of each ilium for articulation with each dorsosacral rib. Additionally, we provide the first detailed description of the vertebral junction formed by two anteriorly projecting flanges on the first primordial sacral ribs and their corresponding facets on the centrum of the dorsosacral. Computed tomographic (CT) imaging reveals that the two primordial sacrals are not co-ossified and that the dorsosacral morphology of this specimen is not the result of obvious pathology. We place this incorporation of a trunk vertebra into the phytosaurian sacrum in a broader evolutionary context, with this shift in vertebral identity occurring at least seven times independently among Triassic archosauriforms, including at least three times in early crocodylian-line archosaurs and at least four times among bird-line archosaurs. Additionally, anteriorly projecting flanges of sacral ribs which articulate with the anterior-adjacent centrum have evolved several times in archosauriforms, and we interpret ‘shared’ sacral ribs (= a sacral rib that articulates with two adjacent sacral centra more or less equally) present in some archosaurian clades as a more extreme example of this morphology. In extant taxa the highly conserved Hox gene family plays a central role in the patterning of the axial skeleton, especially vertebral identity; therefore, the independent incorporation of a trunk vertebra into the sacrum across multiple archosauriform lineages may suggest a homologous underlying developmental mechanism for this evolutionary trend.
... The centra are taller than long (Fig. 11A) suggesting they represent part of the anterior (post-axial) series (i.e., positions 3-6). Most notably, the difference in dimensions is not as pronounced as in Typothorax coccinarum and Neoaetosauroides engaeus, in which the centra are greatly reduced in length (Long & Murry, 1995;Desojo & Báez, 2005;Heckert et al., 2010). The centrum faces are subcircular in anterior and posterior views and slightly concave, with slightly flared rims (Figs. ...
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Aetosaurians are some of the most common fossils collected from the Upper Triassic Chinle Formation of Arizona, especially at the Petrified Forest National Park (PEFO). Aetosaurians collected from lower levels of the park include Desmatosuchus spurensis , Paratypothorax , Adamanasuchus eisenhardtae , Calyptosuchus wellesi , and Scutarx deltatylus . Four partial skeletons collected from the park between 2002 and 2009 represent the holotype and referred specimens of Scutarx deltatylus . These specimens include much of the carapace, as well as the vertebral column, and shoulder and pelvic girdles, and a new naming convention proposed for osteoderms descriptions better differentiates portions of the carapace and ventral armor. A partial skull from the holotype specimen represents the first aetosaur skull recovered and described from Arizona since the 1930s. The key morphological feature distinguishing Scutarx deltatylus is the presence of a prominent, triangular boss located in the posteromedial corner of the dorsal surface of the dorsal paramedian osteoderms. Scutarx deltatylus can be distinguished from closely related forms Calyptosuchus wellesi and Adamanasuchus eisenhardtae not only morphologically, but also stratigraphically. Thus, Scutarx deltatylus is potentially an index taxon for the upper part of the Adamanian biozone.
... [Ordered]. Desojo (2005), character 12. Figures 1b, e. ...
... In contrast, Stagonolepis robertsoni (Walker, 1961) and Neoaetosauroides engaeus (Desojo & Báez, 2005) have tall neural spines that are more than the height of the centrum. This character is restricted to the mid-trunk series because in Scutarx deltatylus, the anterior and mid-trunk vertebrae have neural spines that are shorter than the centrum. ...
... Walker (1961:145) described the subglenoid region of the coracoid of Stagonolepis robertsoni as bearing "a depressed area bounded in front by a stout pillar which makes a slight projection in the medial margin and thus divides the outer surface into two areas". The first area contains the coracoid foramen and receives the insertion of M. supracoracoideus; whereas the second area is the insertion area for M. coracobranchialis (Desojo, 2005). A subglenoid pillar is also present in Typothorax coccinarum (Long & Murry, 1995) and absent in Aetosauroides scagliai and Longosuchus meadei (Desojo, 2005). ...