taxonID	type	description	language	source
B00687C9FFB2E37BFF1C843DBDF7FABE.taxon	description	The cross section of the bone has been affected by diagenetic processes, with a collapse of the cortical surface that partially infilled into the medullary cavity. The diagenetic alterations do not affect the main features of bone microstructure. The cortex is sparsely vascularized, in contrast to the femur of others specimens (Marsà et al. 2020; Ponce et al. 2021). The vascular canals are configured as longitudinally oriented primary osteons. The cortex is conformed by PFB and is interrupted by one LAG (Fig. 2 A). Vascularization is very sparse, even null, in the subperiosteal area. The medullary cavity is separated from the cortex by a resorption line, and it is infilled by a dense trabecular bone tissue, conformed by lamellar bone tissue. The density of osteocyte lacunae across the cortex is low (Fig. 2 B), contrasting with the high density of osteocyte lacunae present throughout the femoral cortex of other specimens (Marsà et al. 2020; Ponce et al. 2021). Their morphology ranges from circular to subcircular in both cortex and trabecular bone. The distribution between the osteocyte lacunae is equidistant. TIBIA (PULR-V 116) The cross section of the bone has been affected by diagenetic processes, being fractured in several areas and collapsing towards the medullary cavity. However, these diagenetic alterations do not affect the main features of bone microstructure. The cortex is almost avascular, with a few longitudinal canals, few secondary osteons, and interrupted by three LAGs (Fig. 3 A). The cortex is constituted of LB and shows cyclical growth, with the presence of three LAGs. Some areas of the cortex present Sharpey’s fibers. The medullary cavity is infilled by a dense network of trabecular cancellous bone, tissue that is separated from the compact cortex by an ATZ (Fig. 3 A, B), and conformed by lamellar bone tissue. Trabeculae are thicker than those described in the femur PULR-V 116. The density of osteocyte lacunae is high (Fig. 3 B), contrasting with the low density of osteocyte lacunae present along the cortex of the femur PULR-V 116. These osteocyte lacunae are mostly circular in morphology, and orderly distributed. The osteocyte lacunae of the innermost cortex, adjacent to the CCCB, have a more elongated morphology. FIBULA (PULR-V 116) The cross section of the fibula has been affected by diagenesis, with the medullary cavity partially infilled by fragments of the cortex. But these diagenetic alterations do not affect the main features of bone microstructure. The cortex is highly vascularized, in contrast to the femur and tibia of the same specimen (Fig. 4), resembling the femur of specimen PULR-V 125 (Marsà et al. 2020). The vascular canals are formed of primary osteons mostly longitudinally oriented, but some osteons exhibit a reticular pattern. A laminar arrangement of the primary osteons is also visible, but to a much lesser extent. In the inner cortex there are numerous secondary osteons. The half of the outer cortex closest to the subperiosteum consists of FLB and shows cyclical growth, with the presence of three LAGs (Fig. 4). Regarding the LAGs and their location in the FLB cortex: the first is a double LAG located at the middle of the FLB, and the last is located close to the subperiosteum. A thin layer of PFB forms around the LAGs. The medullary cavity is reduced in comparison to the thickness of the cortex and infilled by trabecular bone tissue (Fig. 4). A high density of osteocyte lacunae with oval morphology and irregular distribution are present throughout the cortex.	en	Marsà, Jordi Alexis Garcia, Ponce, Denis A., Agnolín, Federico Lisandro, Novas, Fernando E. (2023): Histovariability and lifestyle in Proterochampsidae Romer, 1966 (Archosauriformes) from the Chañares Formation (Late Triassic), northwestern Argentina. Comptes Rendus Palevol 22 (30): 605-622, DOI: 10.5852/cr-palevol2023v22a30, URL: http://dx.doi.org/10.5852/cr-palevol2023v22a30
B00687C9FFBDE37AFCB5879DBB58F89C.taxon	description	The transverse section of the bone is well preserved, although part of the cortex collapsed and infilled inside the medullary cavity. The cortex formed by PFB is densely vascularized (Fig. 5), even more than in the femur cortex of specimen PVL- 4604 (Marsà et al. 2020). The vascular canals are mainly longitudinally and circumferentially arranged, which give rise to a laminar vascular organization (Fig. 5). Similar to PVL- 4604 (Marsà et al. 2020), there is a reduction in the density of primary osteons towards the subperiosteum. The cortex is not interrupted by growth marks. The medullary cavity is surrounded by a layer of lamellar bone tissue deposited endosteally, forming the ICL, which is thicker than in PVL- 4604 (Marsà et al. 2020). In this specimen the osteocyte lacunae are difficult to distinguish, probably due to diagenesis, and are less abundant than in Chanaresuchus bonapartei PULR-V 116 or Tropidosuchus romeri PVL- 4604 (Marsà et al. 2020). The osteocyte lacunae are subcircular in outline and present throughout the cortex, as well as in the ICL, but in very low numbers in the latter.	en	Marsà, Jordi Alexis Garcia, Ponce, Denis A., Agnolín, Federico Lisandro, Novas, Fernando E. (2023): Histovariability and lifestyle in Proterochampsidae Romer, 1966 (Archosauriformes) from the Chañares Formation (Late Triassic), northwestern Argentina. Comptes Rendus Palevol 22 (30): 605-622, DOI: 10.5852/cr-palevol2023v22a30, URL: http://dx.doi.org/10.5852/cr-palevol2023v22a30
