Simple Summary Two independent research groups led by Olivares (Spain) and Lowenstein (USA) investigated the immunological reactions of proteins extracted from the controversial Orce skull (VM-0), a 1.3-million-year-old fossil found at the Venta Micena site in Orce, Granada (Spain) and initially believed to come from an unidentified hominin. Work by both groups with polyclonal and monoclonal antibodies showed that proteins from this fossil reacted most strongly to antibodies against modern human proteins. Other hominin and mammal fossils from Venta Micena were also studied. Abstract Proteomics methods can identify amino acid sequences in fossil proteins, thus making it possible to determine the ascription or proximity of a fossil to other species. Before mass spectrometry was used to study fossil proteins, earlier studies used antibodies to recognize their sequences. Lowenstein and colleagues, at the University of San Francisco, pioneered the identification of fossil proteins with immunological methods. His group, together with Olivares’s group at the University of Granada, studied the immunological reactions of proteins from the controversial Orce skull fragment (VM-0), a 1.3-million-year-old fossil found at the Venta Micena site in Orce (Granada province, southern Spain) and initially assigned to a hominin. However, discrepancies regarding the morphological features of the internal face of the fossil raised doubts about this ascription. In this article, we review the immunological analysis of the proteins extracted from VM-0 and other Venta Micena fossils assigned to hominins and to other mammals, and explain how these methods helped to determine the species specificity of these fossils and resolve paleontological controversies.

/pdf/twentieth-century-paleoproteomics-lessons-from-venta-micena-1ymq0t51.pdf

Twentieth-Century Paleoproteomics: Lessons from Venta Micena Fossils

The use of non‐destructive approaches for digital acquisition (e.g. computerised tomography—CT) allows detailed qualitative and quantitative study of internal structures of skeletal material. Here, we present a new R‐based software tool, Icex, applicable to the study of the sizes and shapes of skeletal cavities and fossae in 3D digital images. Traditional methods of volume extraction involve the manual labelling (i.e. segmentation) of the areas of interest on each section of the image stack. This is time‐consuming, error‐prone and challenging to apply to complex cavities. Icex facilitates rapid quantification of such structures. We describe and detail its application to the isolation and calculation of volumes of various cranial cavities. The R tool is used here to automatically extract the orbital volumes, the paranasal sinuses, the nasal cavity and the upper oral volumes, based on the coordinates of 18 cranial anatomical points used to define their limits, from 3D cranial surface meshes obtained by segmenting CT scans. Icex includes an algorithm (Icv) for the calculation of volumes by defining a 3D convex hull of the extracted cavity. We demonstrate the use of Icex on an ontogenetic sample (0–19 years) of modern humans and on the fossil hominin crania Kabwe (Broken Hill) 1, Gibraltar (Forbes' Quarry) and Guattari 1. We also test the tool on three species of non‐human primates. In the modern human subsample, Icex allowed us to perform a preliminary analysis on the absolute and relative expansion of cranial sinuses and pneumatisations during growth. The performance of Icex, applied to diverse crania, shows the potential for an extensive evaluation of the developmental and/or evolutionary significance of hollow cranial structures. Furthermore, being open source, Icex is a fully customisable tool, easily applicable to other taxa and skeletal regions.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/joa.13843

Icex: Advances in the automatic extraction and volume calculation of cranial cavities

Previous studies on the morphology of the inner ear (semicircular canals and cochlea) in the Sima de los Huesos hominin sample have provided important results on the evolution of these structures in the Neandertal lineage. Similarly, studies of the anatomy of the external and middle ear cavities of the Sima de los Huesos hominins have also provided important data on the auditory capacities of this European Middle Pleistocene population. The present contribution provides unpublished data on three new middle ear variables from the Sima de los Huesos fossils and compares these data with values from samples of Pan troglodytes, Homo neanderthalensis and Homo sapiens. The results of this analysis are combined with those obtained in previous studies to characterize the anatomy of the outer, middle and inner ear in the Sima de los Huesos fossils, as well as to establish the order of appearance of the features that characterize Neandertal ears. As in other cranial structures, the ear region in the Sima de los Huesos show a mosaic evolutionary pattern that includes primitive traits, others shared exclusively with Neandertals, and others that are specific to the Sima de los Huesos hominins. Neandertals and Sima de los Huesos hominins share two exclusive features of the middle ear that are among the first characteristics of the Neandertal lineage: a long tympanic cavity and a large entrance and exit of the mastoid antrum. Along with these traits, the Sima de los Huesos hominins present two specialized features: large volumes of the tympanic cavity and the mastoid antrum. Finally, the middle ear of the Neandertals is characterized by the presence of small angles between the tympanic axis and the plane of the oval window.

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/ar.25181

The ear of the Sima de los Huesos hominins (Atapuerca, Spain).

Geometric morphometric analysis of the bony labyrinth of the Sima de los Huesos hominins.

The presence of a coiled cochlea is a unique feature of the therian inner ear. While some aspects of the cochlea are already known to affect hearing capacities, the full extent of the relationships between the morphology and function of this organ are not yet understood-especially when the effect of body size differences between species is minimized. Here, focusing on Euarchontoglires, we explore cochlear morphology of 33 species of therian mammals with a restricted body size range. Using μCT scans, 3D models and 3D geometric morphometrics, we obtained shape information of the cochlea and used it to build phylogenetically corrected least square models with 12 hearing variables obtained from the literature. Our results reveal that different taxonomic groups differ significantly in cochlea shape. We further show that these shape differences are related to differences in hearing capacities between these groups, despite of similar cochlear lengths. Most strikingly, rodents with good low-frequency hearing display "tower-shaped" cochleae, achieved by increasing the degree of coiling of their cochlea. In contrast, primates present relatively wider cochleae and relative better high frequency hearing. These results suggest that primates and rodents increased their cochlea lengths through different morpho-evolutionary trajectories. 

https://www.nature.com/articles/s41598-023-29478-z.pdf

Lisa Schisanowski

Papers

Cochlear morphology of Indonesian Homo erectus from Sangiran.