callenderi take to, whose mid-diaphysis biggest axis diameter range regarding 14.4 (PEFO 34561) to help you twenty two.step 1 mm (PEFO 33991). 1, which is just below the fresh new mean (sixteen.4 mm) and you can just as the median size (15.cuatro mm) of one’s attempt. Even in the event size is perhaps not the greatest proxy to own ontogeny (Griffin ainsi que al., 2020 ), the current presence of drastically big femora (PEFO 33991 and you may 35318) together with insufficient an enthusiastic EFS during the PEFO 33843 one another mean the second individual wasn’t fully grown, though it had most likely passed the point of inflection in its gains bend. For this reason, we could hypothesize that every of your own specimens within this investigation was neither very early juveniles otherwise adults regarding good skeletal readiness perspective.
5.9.dos Paramedian osteoderms
When you look at the researching brand new osteohistology of one’s tested paramedian osteoderms regarding Roentgen. callenderi and Krzyzanowskisaurus hunti, you will need to observe that certain seen type could be because of positional consequences, in terms of the new osteoderm’s exact area from the carapace and you can in which over the osteoderm the fresh histological point is actually drawn. Lower than, we establish the 2 osteoderms together with her, explicitly detailing in which it differ.
For instance the femur, brand new tested paramedian osteoderm out-of Roentgen. callenderi (PEFO 33940a) possess a thinner layer of sparry calcite (Rates 13f, i), while brand new osteoderm away from K. hunti (UCMP 175058) possess a layer regarding emerald-coloured glue, possibly shellac (Rates 13h, j). Cracks and you may internal places off both issues try permineralized of the calcite spar. Short zones of UCMP 175058 is actually permineralized because of the a keen opaque yellow-brownish mineral (Numbers 13h, j), almost certainly an iron mineral such as for instance siderite otherwise hematite. Each other specimens display screen a number of large breaks with displacement and you can better number of reduced hairline fractures (Numbers 13e–j) but they are if not well-kept.
Evidence off reducing development, however, no EFS, was broadly consistent with the proportions set of femora in the PEFO Roentgen
Both osteoderms is actually mostly lightweight cortical bone with a comparatively short quantity of moderately size of vascular rooms (Data 13f–j); this type of places is actually smaller compared to those individuals present in brand new aetosauriform An excellent. geoffreyi ( : fig. 8), however, bigger versus densely-packaged small areas that define inner cancellous tissues during the aetosaurs (Cerda ainsi que al., 2018 ; Cerda & Desojo, 2011 ; Parker ainsi que al., 2008 ; Scheyer ainsi que al., 2014 ). While the noticed because of the Scheyer ainsi que al. ( 2014 : pg. 255) to possess a small paramedian osteoderm regarding Roentgen. callenderi, this type of endosteal areas is rimmed of the second lamellar structure; the new secondary muscle filling such areas is much more thorough on the osteoderm of K. hunti (Numbers 13h, j). On sample regarding K. hunti, the fresh new ventral border on the renovated area models reasonable discontinuity between your second muscle and no. 1 tissues of your own basal cortex (gray arrow within the Profile 13j) that is just like the resorption line Cerda et al. ( 2018 ) described for aetosaurs, however, which border is actually reduced line of from inside the Roentgen. callenderi (Figure 13i). On the other hand, the basal cortex in both specimens is virtually completely avascular, save your self for many commonly spaced effortless streams and faceflow hile you can pri ) noticed for Revueltosaurus together with symptom in A beneficial. geoffreyi ( ), while aetosaurs seem to be some a great deal more vascular in this field (Cerda ainsi que al., 2018 ; Scheyer et al., 2014 ). Which first bone of the basal cortex comprises parallel-fibered tissue, but does not have the brand new laminar surface revealed to own A beneficial. geoffreyi (cf. , p. 16). The fresh new basal cortex of one’s R. callenderi osteoderm and has now seemingly plentiful Sharpey’s material in the a top position on the enough time axis of the cross-part (Contour 13i, just like the reputation present in certain aetosaurs (cf. Cerda et al., 2018 : fig. 7g–h), whereas they look to get absent when you look at the K. hunti (Figure 13j).