More on the Liang Bua finds and modern human cretins

Six new examples of the bipartite trapezoid bone: Morphology, significant population variation, and an examination of pre-existing criteria to identify bipartition of individual carpal bones

“…Both the textual records and actual skeletons of the documented anatomical cases from the Raymond Dart Anatomical collection were examined for evidence of congenital hypothyreosis but a positive diagnosis of this condition could not be supported. Bipartition of the trapezoid has been recently cited as a possible explanation of the trapezoid morphology attributed to Homo floresiensis (Flores, Indonesia), as part of a broader argument suggesting cretinism best explains the late Pleistocene skeletal remains (Obendorf et al, 2008;Oxnard et al, 2012). Though this assertion has been refuted elsewhere (Brown, 2012;Orr et al, 2013), our review of morphological characteristics of the bipartite trapezoid and its articulations may provide additional clarity to this debate and to the identification of further cases.…”

“…Although carpal bipartition is not typically considered a characteristic of congenital hypothyreosis, a bipartite scaphoid has been noted in an affected individual (e.g., O'Rahilly, 1953) and delayed or under-ossification of the palmar portion of the normal trapezoid has been reported in association with the condition (Obendorf et al, 2008;Oxnard et al, 2012). Both the textual records and actual skeletons of the documented anatomical cases from the Raymond Dart Anatomical collection were examined for evidence of congenital hypothyreosis but a positive diagnosis of this condition could not be supported.…”

Homo floresiensis Contextualized: A Geometric Morphometric Comparative Analysis of Fossil and Pathological Human Samples

“…These small differences are unlikely to influence the results of the analyses presented here. While concerns have been raised about the preservation conditions of LB1 upon its discovery [18], [34], analyses of cranial asymmetry suggest that its level of asymmetry is comparable to other wild-shot, non-pathological African ape crania and to well-studied – and presumably non-pathological – fossil hominin crania [3], [35]. As discussed by Kaifu et al [8], [54], the deformation that is present in the LB1 cranium can probably be explained by positional deformational plagiocephaly, a condition that results from plastic deformation of the skull during infancy, but without serious health effects.…”

“…However, more recent work by Oxnard and colleagues [19], [34] has taken issue with Brown [43], and presented new evidence, primarily from the postcranial skeleton, supporting ME hypothyroidism. While the findings in this recent study have yet to be fully evaluated by the scientific community, Orr et al [27], using new fossil specimens and a large comparative sample, have shown that the wrist morphology of the Flores hominins is likely plesiomorphic rather than pathological [contra 17, 18].…”

Role of maternal thyroid hormones in the developing neocortex and during human evolution

“…However, this condition is less severe than neurological cretinism which is characterized by severe neurological lesions without clinical hypothyroidism caused by severe iodine deficiency resulting in low maternal thyroid hormones during first half of gestation (Obendorf et al, 2008). Further examinations of cretin postcrania reveal evidence that cretins share numerous postcranial features with H. floresiensis (Oxnard et al, 2010, 2012). In agreement with these findings, analyses of human genetic variation revealed genomic regions that show signs of selection in the short-statured African Pygmy group; two of these regions concern the thyroid hormone pathway.…”