Person:
Martínez Mendizábal, Ignacio

First Name

Ignacio

Last Name

Martínez Mendizábal

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Area

Paleontología

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Now showing 1 - 10 of 26

Human calcanei from the Middle Pleistocene site of Sima de los Huesos (Sierra de Atapuerca, Burgos, Spain)
(Elsevier, 2014-11) Pablos, Adrián; Martínez Mendizábal, Ignacio; Lorenzo, Carlos; Sala Burgos, Nohemi; Gracia Téllez, Ana; Arsuaga, Juan Luis
The existence of calcanei in the fossil record prior to modern humans and Neandertals is very scarce. This skeletal element is fundamental to understanding the evolution of the morphology of the foot in human evolution. Here we present and metrically and comparatively describe 29 calcaneus remains from the Middle Pleistocene site of Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain). These calcanei belong to 15 individuals (nine adults, two adolescents and four immature individuals). The metric and morphological differences in the calcanei among Middle and Late Pleistocene hominins tend to be subtle. However, the calcanei from SH are broad and robust with large articular surfaces and most significantly, exhibit a very projected sustentaculum tali. A biomechanical and phylogenetic interpretation is proffered to explain the observed morphology of these calcanei. It has been possible to propose tentative sex assignments for the SH calcanei based on size, using methods similar to those used to establish sex from the talus bones from SH. The estimation of stature based on the calcaneus provides a mean of 175.3 cm for males and 160.6 for females, which is similar to that obtained using other skeletal parts from the site. In sum, the SH calcanei are robust with a proportionally long tubercle and a projected sustentaculum tali, which are traits shared by Neandertals.
Revisión de la mandíbula humana de Bañolas, Gerona, España
(Real Sociedad Española de Historia Natural, 2011) Alcázar de Velasco, Almudena; Arsuaga, Juan Luis; Martínez Mendizábal, Ignacio; Bonmatí, Alejandro
La mandíbula de Bañolas, descubierta en 1887 en Bañolas (Gerona, España), es un fósil humano sobre cuya asignación taxonómica no hay aún consenso. En diferentes estudios ha sido incluida dentro de Homo neanderthalensis {King, 1864} (Hernández-Pacheco & Obermaier, 1915; Sánchez, 1993), dentro de los ante-neandertales (de Lumley, 1971-72) y dentro de los ante-würmienses (Roth & Simon, 1993). Recientemente, Daura y colaboradores (Daura et al., 2005), en su artículo sobre la mandíbula fósil de la Cova del Gegant, sugieren que la mandíbula de Bañolas no presenta caracteres neandertales y que, dada su cronología, podría haber pertenecido a un Homo sapiens {Linneo, 1758}. Este estudio trata de arrojar luz sobre la cuestión de la asignación taxonómica de la mandíbula de Bañolas. Para ello se han utilizado caracteres morfológicos discretos que permiten discriminar entre las especies H. heidelbergensis {Schoetensack, 1908}, H. neanderthalensis y H. sapiens. La conclusión del trabajo es que los estados de los caracteres que presenta la mandíbula de Bañolas son, en su mayor parte, más frecuentes en H. sapiens que en las otras dos especies tenidas en cuenta.
Orofacial pathology in Homo heidelbergensis: The case of Skull 5 from the Sima de los Huesos site (Atapuerca, Spain)
(Elsevier, 2013-05-08) Gracia-Téllez, Ana; Arsuaga Ferreras, Juan Luis; Martínez Mendizábal, Ignacio; Martín Francés, Laura; Martinón Torres, María; Bermúdez de Castro, José María; Bonmatí, Alejandro; Lira, Jaime
This paper presents a detailed palaeopathological study of the orofacial lesions present in Skull 5 from the Sima de los Huesos Middle Pleistocene site. Besides testing a previous diagnosis of periodontal disease, tooth wear, left P3 fracture and two periapical abscesses, unreported lesions are identified: the I1 abscess and the M3 fracture. The timing of the pathological events that have produced the conspicuous bone growth of the maxilla was determined with the aid of computer tomography techniques. This is particularly important to assess the duration/chronicity of the lesions and the cause/s of them. Some physiological particularities of the region affected could account for the maxillary osteitis and concomitant infection as a probable cause of death.
Carnivore activity in the Sima de los Huesos (Atapuerca, Spain) hominin sample
(Elsevier, 2014-08-01) Sala Burgos, Nohemi; Arsuaga, Juan Luis; Martínez Mendizábal, Ignacio; Gracia Téllez, Ana
The Sima de los Huesos (SH) site is the largest accumulation of human remains from the Middle Pleistocene known to date. Studies in the last two decades have proposed different hypotheses to explain carnivore activity in the SH human sample. This study provides new data in order to test these different interpretations, and therefore to understand the role of the carnivores in site formation at SH. Carnivores are usually not the origin of large accumulations of hominin fossils in the Eurasian record. The results show that marks of carnivore activity in the SH sample appear very infrequently, which we interpret as indicating that carnivore activity was very sporadic at the site. This is in stark contrast with previous studies. The comparison of bone modification patterns at SH to actualistic carnivore data allows us to suggest that bears were likely to have been the carnivore responsible for the modification observed on both human and bear fossils
Reassessment of the La Ferrassie 3 Neandertal ossicular chain
(Elsevier Science B.V., Amsterdam, 2013) Quam, Rolf; Martínez Mendizábal, Ignacio; Arsuaga, Juan Luis
The ossicular chain in La Ferrassie 3 was briefly described in the monograph on the La Ferrassie Neandertal children, but to date has not been the subject of detailed study. We provide new data on these important fossils and re-examine some previous suggestions of derived Neandertal features in the middle ear ossicles based on more limited evidence. The malleus shows a curved lateral margin of the manubrium and a relatively large head. The incus shows a tall articular facet, a depressed area on the medial surface of the body, a straight anterior border of the long process and a more closed angle between the processes. The stapes shows an asymmetrical configuration of the crura, with an anteriorly skewed head, and generally small dimensions, including a smaller and relatively wider stapedial footplate. These same features can also be seen in the few other Neandertal ear ossicles known, suggesting that a consistent anatomical pattern characterizes the Neandertal ossicular chain. While the phylogenetic polarity of many of these features remains to be clarified, the asymmetrical stapes and anteriorly skewed stapedial head appear to be derived Neandertal features. In addition, while the larger malleus head and incus articular facet in La Ferrassie 3 might reflect larger body mass in Neandertals, the larger stapes footplates in Homo sapiens cannot be explained by changes in body mass. Indeed, H. sapiens seems to depart from the general mammalian pattern in combining an increase in stapes footplate size with a decrease in body mass. Although the malleus/incus lever ratio in La Ferrassie 3 is similar to that in H. sapiens, Neandertals appear to be characterized by a slightly different spatial relationship and articulation of the ossicular chain within the tympanic cavity. While only limited inferences can be drawn regarding hearing ability based on the ossicles, the few physiologically relevant dimensions in the La Ferrassie 3 ear bones are similar to H. sapiens.
Auditory capacities of human fossils: A new approach to the origin of speech
(Société française d'acoustique, Acoustical Society of America, European Acoustics Association, 2008) Martínez Mendizábal, Ignacio; Quam, Rolf Michael; Rosa Zurera, Manuel; Jarabo, Pilar; Lorenzo, Carlos; Arsuaga, Juan Luis
The origin and evolution of human language has mainly dealt with the reconstruction of the upper respiratory tract of human fossils. After decades of controversy no clear results have arisen from these studies. We propose a new approach to this issue based on the possibility to reconstruct the sound power transmission, through the external and middle ear, in fossil specimens. The results thus obtained in the more than 500 kyr old fossils from the Sima de los Huesos site (Sierra de Atapuerca, Spain) show that these hominins had the same auditory capacities as modern humans. Specifically, they show a widened bandwidth of heightened sensitivity in the midrange frequencies compared with chimpanzees. Relying on the theory of communication as developed by Shannon, this widened bandwidth suggests a greater channel capacity characterized the Atapuerca (SH) hominins and is consistent with other recent suggestions foring an ancient origin for human speech capacity.
The Neandertal nature of the Atapuerca Sima de los Huesos mandibles
(Wiley Periodicals, 2023-03-30) Quam, Rolf; Martínez Mendizábal, Ignacio; Rak, Yoel; Hylander, Bill; Pantoja Pérez, Ana; Lorenzo, Carlos; Conde Valverde, Mercedes; Keeling, Brian A.; Ortega Martínez, María Cruz; Arsuaga, Juan Luis
The recovery of additional mandibular fossils from the Atapuerca Sima de los Huesos (SH) site provides new insights into the evolutionary significance of this sample. In particular, morphological descriptions of the new adult specimens are provided, along with standardized metric data and phylogenetically relevant morphological features for the expanded adult sample. The new and more complete specimens extend the known range of variation in the Atapuerca (SH) mandibles in some metric and morphological details. In other aspects, the addition of new specimens has made it possible to confirm previous observations based on more limited evidence. Pairwise comparisons of individual metric variables revealed the only significant difference between the Atapuerca (SH) hominins and Neandertals was a more vertical symphysis in the latter. Similarly, principal components analysis of size-adjusted variables showed a strong similarity between the Atapuerca (SH) hominins and Neandertals. Morphologically, the Atapuerca (SH) mandibles show nearly the full complement of Neandertal-derived features. Nevertheless, the Neandertals differ from the Atapuerca (SH) mandibles in showing a high frequency of the H/O mandibular foramen, a truncated, thinned and inverted gonial margin, a high placement of the mylohyoid line at the level of the M3, a more vertical symphysis and somewhat more pronounced expression of the chin structures. Size-related morphological variation in the SH hominins includes larger retromolar spaces, more posterior placement of the lateral corpus structures, and stronger markings associated with the muscles of mastication in larger specimens. However, phylogenetically relevant features in the SH sample are fairly stable and do not vary with the overall size of the mandible. Direct comparison of the enlarged mandibular sample from Atapuerca (SH) with the Mauer mandible, the type specimen of H. heidelbergensis, reveals important differences from the SH hominins, and there is no morphological counterpart of Mauer within the SH sample, suggesting the SH fossils should not be assigned to this taxon. The Atapuerca (SH) mandibles show a greater number of derived Neandertal features, particularly those related to midfacial prognathism and in the configuration of the superior ramus, than other European middle Pleistocene specimens. This suggests that more than one evolutionary lineage co-existed in the middle Pleistocene, and, broadly speaking, it appears possible to separate the European middle Pleistocene mandibular remains into two distinct groupings. One group shows a suite of derived Neandertal features and includes specimens from the sites of Atapuerca (SH), Payre, l'Aubesier and Ehringsdorf. The other group includes specimens that generally lack derived Neandertal features and includes the mandibles from the sites of Mauer, Mala Balanica, Montmaurin and (probably) Visogliano. The two published Arago mandibles differ strongly from one another, with Arago 2 probably belonging to this former group, and Neandertal affinities being more difficult to identify in Arago 13. Outside of the SH sample, derived Neandertal features in the mandible only become more common during the second half of the middle Pleistocene. Acceptance of a cladogenetic pattern of evolution during the European middle Pleistocene has the potential to reconcile the predictions of the accretion model and the two phases model for the appearance of Neandertal morphology. The precise taxonomic classification of the SH hominins must contemplate features from the dentition, cranium, mandible and postcranial skeleton, all of which are preserved at the SH site. Nevertheless, the origin of the Neandertal clade may be tied to a speciation event reflected in the appearance of a suite of derived Neandertal features in the face, dentition and mandible, all of which are present in the Atapuerca (SH) hominins. This same suite of features also provides a useful anatomical basis to include other European middle Pleistocene mandibles and crania within the Neandertal clade.
Fossil hominin radii from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain)
(Elsevier, 2016-01) Rodríguez, Laura; Carretero, José Miguel; García González, Rebeca; Lorenzo, Carlos; Gómez Olivencia, Asier; Quam, Rolf; Martínez Mendizábal, Ignacio; Gracia Téllez, Ana; Arsuaga, Juan Luis
Complete radii in the fossil record preceding recent humans and Neandertals are very scarce. Here we introduce the radial remains recovered from the Sima de los Huesos (SH) site in the Sierra de Atapuerca between 1976 and 2011 and which have been dated in excess of 430 ky (thousands of years) ago. The sample comprises 89 specimens, 49 of which are attributed to adults representing a minimum of seven individuals. All elements are described anatomically and metrically, and compared with other fossil hominins and recent humans in order to examine the phylogenetic polarity of certain radial features. Radial remains from SH have some traits that differentiate them from those of recent humans and make them more similar to Neandertals, including strongly curved shafts, anteroposterior expanded radial heads and both absolutely and relatively long necks. In contrast, the SH sample differs from Neandertals in showing a high overall gracility as well as a high frequency (80%) of an anteriorly oriented radial tuberosity. Thus, like the cranial and dental remains from the SH site, characteristic Neandertal radial morphology is not present fully in the SH radii. We also analyzed the cross-sectional properties of the SH radial sample at two different levels: mid-shaft and at the midpoint of the neck length. When standardized by shaft length, no difference in the mid-shaft cross-sectional properties were found between the SH hominins, Neandertals and recent humans. Nevertheless, due to their long neck length, the SH hominins show a higher lever efficiency than either Neandertals or recent humans. Functionally, the SH radial morphology is consistent with more efficient pronation-supination and flexion-extension movements. The particular trait composition in the SH sample and Neandertals resembles more closely morphology evident in recent human males.
Nuclear DNA sequences from the Middle Pleistocene Sima de los Huesos hominins
(Macmillan, 2016-03-24) Meyer, Matthias; Arsuaga, Juan Luis; Filippo, Cesare de; Nagel, Sarah; Aximu-Petri, Ayinuer; Nickel, Birgit; Martínez Mendizábal, Ignacio; Gracia Téllez, Ana; Bermúdez de Castro, José María; Carbonell, Eudald; Viola, Bence; Kelso, Janet; Prüfer, Kay; Pääbo, Svante
A unique assemblage of 28 hominin individuals, found in Sima de los Huesos in the Sierra de Atapuerca in Spain, has recently been dated to approximately 430,000 years ago. An interesting question is how these Middle Pleistocene hominins were related to those who lived in the Late Pleistocene epoch, in particular to Neanderthals in western Eurasia and to Denisovans, a sister group of Neanderthals so far known only from southern Siberia. While the Sima de los Huesos hominins share some derived morphological features with Neanderthals, the mitochondrial genome retrieved from one individual from Sima de los Huesos is more closely related to the mitochondrial DNA of Denisovans than to that of Neanderthals. However, since the mitochondrial DNA does not reveal the full picture of relationships among populations, we have investigated DNA preservation in several individuals found at Sima de los Huesos. Here we recover nuclear DNA sequences from two specimens, which show that the Sima de los Huesos hominins were related to Neanderthals rather than to Denisovans, indicating that the population divergence between Neanderthals and Denisovans predates 430,000 years ago. A mitochondrial DNA recovered from one of the specimens shares the previously described relationship to Denisovan mitochondrial DNAs, suggesting, among other possibilities, that the mitochondrial DNA gene pool of Neanderthals turned over later in their history.
Human talus bones from the Middle Pleistocene site of Sima de los Huesos (Sierra de Atapuerca, Burgos, Spain
(Elsevier Science B.V., Amsterdam, 2013-07) Pablos, Adrián; Martínez Mendizábal, Ignacio; Lorenzo Merino, Carlos; Gracia Téllez, Ana; Sala Burgos, Nohemi; Arsuaga Ferreras, Juan Luis
Here we present and describe comparatively 25 talus bones from the Middle Pleistocene site of the Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain). These tali belong to 14 individuals (11 adult and three immature). Although variation among Middle and Late Pleistocene tali tends to be subtle, this study has identified unique morphological characteristics of the SH tali. They are vertically shorter than those of Late Pleistocene Homo sapiens, and show a shorter head and a broader lateral malleolar facet than all of the samples. Moreover, a few shared characters with Neanderthals are consistent with the hypothesis that the SH population and Neanderthals are sister groups. These shared characters are a broad lateral malleolar facet, a trochlear height intermediate between modern humans and Late Pleistocene H. sapiens, and a short middle calcaneal facet. It has been possible to propose sex assignment for the SH tali based on their size. Stature estimates based on these fossils give a mean stature of 174.4 cm for males and 161.9 cm for females, similar to that obtained based on the long bones from this same site.