Early Cretaceous mammals of Western Siberia: 2. Tegotheriidae

New specimens of the tegotheriid docodont Sibirotherium rossicum Maschenko et al., 2003, including a maxillary fragment with two posterior teeth, an isolated upper molar, and mandibular fragments with teeth from the Early Cretaceous Shestakovo locality are described. The dental formula of Sibirotherium is I_{1 + ?}C1P₆M_6?. The upper molars of Sibirotherium, with two main labial and three lingual cusps, are convergently similar to the molars of tribosphenic mammals. In the dentary, the symphysis is short and Meckel’s groove is reduced. Sibirotherium is similar in the structure of lower teeth to Tegotherium from the Upper Jurassic of Mongolia; it is the latest known representative of Docodonta.     

A new species of Golunda (Rodentia, Muridae) from the Late Pleistocene of Indian Himalaya

The youngest fossil Golunda (Rodentia, Muridae) is described from the Late Pleistocene fluvio-lacustrine deposits, exposed at Dulam (Bageshwar), Kumaun Lesser Himalaya, India. The age of fossiliferrous horizon is estimated as 31,000 yr BP. A new species, Golunda dulamensis nov. sp. has highly derived characters, e.g., antero-posteriorly stretched molars, upper molars with more length and less width, stephanodonty, cusps in M₃ strongly inclined backward giving the molars a very stretched aspect, and metaconid and entoconid in M₃ forming almost straight lingual row of the cusps. G. dulamensis nov. sp. is most similar to present day G. ellioti but differs from the later slightly by larger size, a thin connection between t₄ and t₅ in M¹, and comparatively larger entoconid and very weakly developed antero-labial cusp in M₃. We suggest that highly specialized molars of G. dulamensis nov. sp. and present day G. ellioti are derivable through G. kelleri. We also propose that Golunda migrated from Asia to Africa, not from Africa to Asia as was thought by earlier workers.     

Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens

Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n = 127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M₁ and M₂ is small. In contrast, Aterian H. sapiens root surface areas peak at M₂. Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens.     

Studies on the structure of the calcium-dependent adenosine triphosphatase from rabbit skeletal muscle sarcoplasmic reticulum

The linear arrangement of the three fragments of Ca²⁺-ATPase from rabbit skeletal muscle sarcoplasmic reticulum with molecular weights of 20,000, 30,000, and 45,000 obtained by limited tryptic hydrolysis was determined by locating the NH₂-terminal acetylated methionyl residue of the original peptide in the M_r = 20,000 fragment. Since both the M_r = 20,000 and 30,000 polypeptides originate from a M_r = 55,000 fragment which is distinct from the M_r = 45,000 polypeptide, the sequence of these three fragments was determined to be 20,000, 30,000, and 45,000. The M_r = 20,000 fragment was further cleaved by cyanogen bromide to yield a M_r = 7,000 COOH-terminal fragment which is relatively hydrophilic. The NH₂-terminal portion is rich in glutamyl residues. The COOH-terminus of the M_r = 30,000 fragment was determined by both digestion with carboxypeptidases and cyanogen bromide cleavage. Using the partial amino acid sequence of the Ca²⁺-ATPase, it was deduced that the active site phosphoaspartyl residue is 154 amino acids from the COOH-terminus of the M_r = 30,000 fragment and hence approximately 35,000 M_r from the NH₂-terminus of the original Ca²⁺-ATPase molecule. Furthermore, it was shown that the two tryptic cleavages of the Ca²⁺-ATPase generating these three large fragments were both single hydrolyses of arginylalanine peptide bonds.     

An unexpected Late Pleistocene macaque remain from Grotta degli Orsi Volanti (Rapino, Chieti, central Italy)

An explosion set off in a limestone quarry located in the surroundings of Rapino (Chieti, central Italy), in the National Park of the Maiella Massif, exposed a small cave containing a Late Pleistocene fauna and Mousterian tools. Amongst the specimens is a fairly well preserved dorsal portion of a left mandibular corpus with associated M₁ and M₂ attributable to Macaca. The Grotta degli Orsi Volanti specimen is the very first macaque ever found in Abruzzo, but it also is one of the most recent, and the southern and easternmost known from Italy.     

New remains of Chambius kasserinensis from the Eocene of Tunisia and evaluation of proposed affinities for Macroscelidea (Mammalia,Afrotheria)

Abstract

Chambius kasserinensis from the late Early or early Middle Eocene Chambi locality, central Tunisia, is undoubtedly the oldest known macroscelidid and possibly the basalmost representative of the order Macroscelidea. Hence, since its discovery in 1986, Chambius has played a key role in analyses focusing on afrotherian and eutherian phylogeny; for instance, as early as 1995, Butler’s review of fossil macroscelideans highlighted the central position of Chambius in the origin of the order. Despite this, Chambius remained poorly known until recently. Here based on new mandibular fragments, well-preserved upper molars and CT scan analysis of the holotype maxilla, Chambius is revised. Its dentition is first described in detail, providing a precise characterization of the genus. Chambius is notably defined by a submolariform P₄ with a three-cusped talonid, a reduced talonid on M₂, and a prominent metaconule on M^1?2. Interestingly, the two transverse lophs of the upper molars are basically formed by preconulecristae, evoking the recently defined peculiar bilophodonty of paenungulates. Comparisons with other Paleogene and modern macroscelidids, European Louisinidae, and North American Apheliscidae are also made, allowing the various hypotheses about the origin and early evolution of macroscelidids to be reviewed.     

Prohylobates (Primates) from the Early Miocene of Libya: A new species and its implications for cercopithecid origins

Prohylobates simonsi n. sp. is described on the basis of a partial mandible with M_2–3 from the region of GebelZelten. It is nearly twice the size of the penecontemporaneous P. tandyi and has a relatively longer M₃, but otherwise is nearly identical in morphology. Prohylobates is the most conservative known cercopithecid, presenting incomplete bilophodonty, possible cingulum remnants, high relative width of M₂ and robust mandibular corpus. The variation in M₃ length is comparable to that within some later cercopithecid species and between the species of Propliopithecus, the Oligocene catarrhine suggested to be nearest the ancestry of the Cercopithecidae. Parapithecus (including Simonsius) is not a cercopithecid ancestor     

The anatomy and systematic position of the early Miocene proconsulid from Meswa Bridge, Kenya

A small collection of fossil catarrhines was recovered from the early Miocene locality of Meswa Bridge in western Kenya between 1978 and 1980. The associated fauna from Meswa Bridge indicates an age older than 20 Ma. Much of the material has been briefly described previously, and its taxonomic status considered. The material can be assigned to a minimum of four individuals, all of which are infants or juveniles. Although the specimens were shown to belong to a distinct species of Proconsul, the taxon was not named, primarily because many of the specimens belonged to immature individuals. Nevertheless, the combined morphological features of the deciduous and permanent teeth allow the diagnosis of a new species of Proconsul, which is formally named here as P. meswae. It is a large-sized species, similar in dental size to P. nyanzae. The main features distinguishing it from all other previously named species of Proconsul are: incisors and deciduous incisors relatively low crowned; upper deciduous canines relatively higher crowned and more robust; molars and deciduous premolars relatively broader and higher crowned, with a more pronounced degree of buccolingual flare and better developed cingula; size differential between molars not as marked; dP₄ with a longer mesial fovea and smaller hypoconulid and distal fovea; P₄ relatively broader, with a better developed buccal cingulum; lower molars less rectangular with a longer mesial fovea, smaller distal fovea, more restricted talonid basin, and a tendency for a smaller hypoconulid; dP⁴ and upper molars with strongly buccolingually splayed roots; mandibular corpus in infants relatively deeper and more slender; maxilla with a well developed canine jugum and fossa. The broader and more flared molars with better developed cingula indicate that the Meswa Bridge species is more primitive than other species of Proconsul. The inference that it is a stem member of the Proconsul clade is consistent with the estimated age of the material.     

Additional materials of Myanmarpithecus yarshensis (Amphipithecidae, Primates) from the middle Eocene Pondaung Formation

Myanmarpithecus yarshensis is an amphipithecid primate from the middle Eocene Pondaung Formation in Myanmar. It was previously known based on maxillary fragments with P⁴–M³ and mandibular fragments with C–P₃ and M_2–3. This study reports new materials for the genus, including a humeral head fragment, a lingual fragment of the right M², a lingual fragment of the right M³, and a left I¹. These new materials were collected from approximately the same point, and likely belonged to the same individual. The upper molar morphology and size of the new materials show similarity to those of the type specimen, indicating that the new materials can be assigned to M. yarshensis. The humeral head is the first postcranial element that is associated with dental materials for amphipithecids. The morphological similarity between the previously reported larger humerus and this specimen confirms the assignment of the former specimen to Amphipithecidae and suggests common locomotor adaptations in the family. The upper central incisor is large relative to the molar fragments, but is within the variation among extant platyrrhines. The tooth is spatulate-shaped and high crowned, and lacks the mesial process, indicating similarity to I¹ of haplorhines and clear differences from that of adapoids. It has been suggested that amphipithecids, including Myanmarpithecus, have affinities with notharctine adapoids, but the morphology of I¹ does not support the notharctine hypothesis of the Amphipithecidae.     

Unravelling the Functional Biomechanics of Dental Features and Tooth Wear

Most of the morphological features recognized in hominin teeth, particularly the topography of the occlusal surface, are generally interpreted as an evolutionary functional adaptation for mechanical food processing. In this respect, we can also expect that the general architecture of a tooth reflects a response to withstand the high stresses produced during masticatory loadings. Here we use an engineering approach, finite element analysis (FEA), with an advanced loading concept derived from individual occlusal wear information to evaluate whether some dental traits usually found in hominin and extant great ape molars, such as the trigonid crest, the entoconid-hypoconulid crest and the protostylid have important biomechanical implications. For this purpose, FEA was applied to 3D digital models of three Gorilla gorilla lower second molars (M₂) differing in wear stages. Our results show that in unworn and slightly worn M₂s tensile stresses concentrate in the grooves of the occlusal surface. In such condition, the trigonid and the entoconid-hypoconulid crests act to reinforce the crown locally against stresses produced along the mesiodistal groove. Similarly, the protostylid is shaped like a buttress to suffer the high tensile stresses concentrated in the deep buccal groove. These dental traits are less functional in the worn M₂, because tensile stresses decrease physiologically in the crown with progressing wear due to the enlargement of antagonistic contact areas and changes in loading direction from oblique to nearly parallel direction to the dental axis. This suggests that the wear process might have a crucial influence in the evolution and structural adaptation of molars enabling to endure bite stresses and reduce tooth failure throughout the lifetime of an individual.     

Human skeletal remains from the cave of Hearths,Makapansgat, Northern Transvaal

A detailed study has been made of the oldest South African Upper Pleistocene hominid remains found in Acheulian context in a well-stratified sealed cave deposit, the Cave of Hearths, Makapansgat, Northern Transvaal. Possibly 55,000 years of age, the remains comprise a juvenile right mandibular body with teeth, and part of a right radius. The mandible is highly robust, markedly prognathous, has a slight to moderate bony chin, an appreciable planum alveolare, a low supraspinous foramen, large alveolar part with big tooth roots, parallel upper and lower borders, a superior transverse torus and poorly developed genial apophysis. The teeth are fairly large, narrow and elongate; M₂ is smaller than M₁; both molars have a +5 cusp pattern, and the first molar shows moderate taurodontism. There is good evidence that the jaw shows congenital lack of M₃: after the Chinese Lantian jaw, this is the second oldest hominid mandible and the first African fossil man with this feature. The radius has a relatively large head atop a disproportionately narrow neck; marked angulation of neck on shaft; and a strongly developed bicipital tubercle. The remains show a cluster of features which ally them with African Neandertaloids and earlier hominids of N.W. Africa. These geographically widespread African remains may represent a transitional population between H. erectus and H. sapiens neanderthalensis. This population has been called by Campbell, this author and others H. sapiens rhodesiensis (after the first-discovered specimen from Broken Hill): to this taxon the Cave of Hearths bones are tentatively assigned.     

Characterization and immunocytochemical demonstration of glucocorticoid receptor using antisera specific to transformed receptor

Cytosolic and nuclear forms of the glucocorticoid receptor were characterized using immunochemical techniques. Antibodies were raised in rabbits to an M_r 58,000 fragment of the transformed (DNA-binding) glucocorticoid receptor purified from rat liver cytosol by DNA-cellulose chromatography and polyacrylamide gel electrophoresis. Antibodies reacted with the transformed receptor form in a radioimmunoassay for glucocorticoid receptor. Western blot analysis of antibody reactivity revealed a single M_r 185,000 receptor form in rat liver cytosol but a smaller M_r 85,000 form in nucleosol, indicating the M_r 85,000 form is the transformed receptor. Furthermore, western blot analysis indicates that the M_r 185,000 receptor undergoes proteolysis during receptor purification and in vitro transformation processes by generating immunochemically similar proteins of smaller molecular weights. An identical M_r 185,000 glucocorticoid receptor was detected in cytosols of four rat tissues; liver, brain, adrenal medulla, and thymus. The glucocorticoid receptor was localized to the cytoplasm and nucleus of rat adrenal medulla cells by immunohistochemistry, demonstrating the existence in vivo of the transformed receptor and translocation of the receptor from cytoplasm to nucleus.     

Tooth Wear Difference Between the Yuanmou Hominoid and <Emphasis Type="Italic">Lufengpithecus</Emphasis>

The Late Miocene hominoids recovered from Lufeng (Lufengpithecus) and Yuanmou of Yunnan Province, China, are among the most numerous hominoid fossils in Eurasia. They have yielded critical evidence for the evolutionary history, biogeography and paleobiology of Miocene hominoids. We examined and compared the wear pattern and differences of 804 molars of the Yuanmou hominoid and Lufengpithecus. Our results indicate that both the upper and lower molars of the Yuanmou hominoids were more heavily worn than those of Lufengpithecus. The wear patterns of the individual molars between the Yuanmou hominoid and Lufengpithecus also are different. The heaviest wear of lower molars of the Yuanmou hominoid occur in M₂, followed by M₁ and M₃. In Lufengpithecus, M₁ and M₃ were more heavily worn than M₂. There are differences in wear between the upper and lower molars for the two hominoids. Among the various factors related to tooth wear, we suggest that the main reason for the tooth wear differences between the Yuanmou hominoid and Lufengpithecus may be that they had different diets. More soft dietary items like leaves and berries were probably consumed by Lufengpithecus, and the Yuanmou hominoid may mainly have feed on harder or frugivorous diets. This result complements findings from previous studies of tooth size proportion, and the development of lower molar shearing crests in the 2 samples. Enamel thickness, living environment, behavior patterns, and population structure also might account for dental wear differences between the Yuanmou hominoid and Lufengpithecus.     

Fossil remains of Macaca sylvanus florentina (Cocchi, 1872) (Primates, Cercopithecidae) from the Early Pleistocene of Quibas (Murcia, Spain)

The macaque material from the Early Pleistocene site of Quibas (Albanilla, Murcia, Spain), including dentognathic remains, isolated teeth and some postcranial bone fragments, is described. Both metrically and morphologically, this sample must be attributed to Macaca sylvanus (the Barbary macaque). This species is currently distributed through North Africa and Gibraltar, but was much more widely distributed during the Plio-Pleistocene, being represented by several European fossil subspecies. Metrical comparisons of dental size and proportions between extant M. s. sylvanus and fossil Macaca sylvanus florentina from the type locality and other Italian sites are undertaken, in order to classify the remains from Quibas at the subspecies level. The results show that the Quibas sample not only fits the range of variation of M. s. florentina from the type locality, but also differs from the extant Barbary macaque condition in several regards. This permits us to formally attribute the material from Quibas to M. s. florentina. The material described in this paper therefore significantly improves the knowledge of this fossil taxon, particularly regarding the upper dentition, and further confirms the taxonomic distinctiveness of this extinct taxon at the subspecies rank. Taken as a whole, M. s. florentina largely overlaps in dental dimensions with M. s. sylvanus, but differs from the latter by displaying (on average): (1) absolutely longer upper molars (especially M¹ and M³); (2) relatively wider upper molars (especially M¹ and M²); (3) longer M³ as compared with the M²; (4) absolutely longer M₁ and M₃; and (5) relatively narrower M₃.     

Occlusal surface pattern of the lower molars and the second deciduous molar among the living Polynesians

The occlusal surface pattern of the lower molars and the second deciduous molar among the Polynesians living in Western Samoa was studied on plaster casts. The following are the characteristic traits of this race. The occlusal surface pattern of the first and second lower molars falls within the range of variation of the Mongoloid racial group. In general, the variation of the furrow pattern is remarkable, but the tendency of reduction of number of cusps is not conspicuous. The frequency of C₆ in the lower molars and C₇ in m₂ is far higher than in any other population, but the frequency of C₇ in M₁ or M₂ is not noticeably different.     

Molecular cloning,sequence analysis,and characterization of a new cell wall hydrolase,CwIL, of Bacillus licheniformis

We have cloned a DNA fragment containing the gene for a cell wall hydrolase from Bacillus licheniformis FD0120 into Escherichia coli. Sequencing of the fragment showed the presence of an open reading frame (ORF; designated as cwlL), which is different from the B. licheniformis cell wall hydrolase gene cwlM, and encodes a polypeptide of 360 amino acids with a molecular mass of 38 994. The enzyme purified from the E. coli clone is an N-acetylmuramoyl-l-alanine amidase, which has a M_r value of 41 kDa as determined by SDS-polyacrylamide gel electrophoresis, and is able to digest B. licheniformis, B. subtilis and Micrococcus luteus cell walls. The nucleotide and deduced amino acid sequences of cwlL are very similar to those of ORF3 in the putative operon xpaL1-xpaL2-ORF3 in B. licheniformis MC14. Moreover, the amino acid sequence homology of CwlL with the B. subtilis amidase CwlA indicates two evolutionarily distinguishable regions in CwlL. The sequence homology of CwlL with other cell wall hydrolases and the regulation of cwlL are discussed.     

Occlusal and morphogenetic field evolution in the dentition of European Nyctitheriidae (Euarchonta,Mammalia)

Abstract

The nyctithere genera Saturninia, Cryptotopos and members of the subfamily Amphidozotheriinae are well-represented by dental remains in the European later Eocene. Their molar occlusal relations are described in detail, demonstrating a diversity of adaptations to insectivory, including dilambdodonty, minor trends in zalambdodonty, development of a large talon shelf in upper first and second molars and a step in the trigon-trigonid shearing surface that provides an extra facet in buccal phase. Minor lingual phase wear is recognized for the first time in the family, but only in relatively worn teeth. Nyctithere molars differ from those of most insectivorous mammals today in having well-developed paraconules and metaconules on upper molars, which in most cases lack a marked bucco-lingual tilt, associated with a more transverse jaw action. Amphidozotherium, however, shows tilting and a basally shifted M¹ hypocone associated with M₁ talonid exodaenodonty and a minor trend in zalambdodonty. Nyctitheres primitively have three deeply notched lobate lower incisors and a large but procumbent premolariform lower canine. Amphidozotheriines have modified their I₃ into a premolariform tooth, by shifting the premolarization field mesially. Amphidozotherium has also shifted this field distally, reducing P_2–3 in size and their roots from two to one.     

A new species of lesser panda Parailurus (Mammalia,Carnivora) from the Pliocene of Transbaikalia (Russia) and some aspects of ailurine phylogeny

A new species of the lesser panda, Parailurus baikalicus sp. nov., from the Pliocene of Transbaikalia is described. In contrast to the European taxa P. anglicus and P. hungaricus, it retains a primitive occlusal pattern of M¹-M², with a concave buccal outline, small mesostyle on M¹, and undeveloped styles on M². At the same time, the Transbaikalian panda is more advanced than other representatives of Parailurus in the upper molars with a reduced lingual cingulum and an enlarged paraconule, which is partially (M¹) or completely (M²) separated from the protocone. This combination of primitive and advanced characters points to the separation of the Asian branch at the earliest stages of the genus development. The Transbaikalian lesser panda may represent a terminal form of this phylogenetic lineage.     

Multiplex genotyping based on the melting temperature of a single locked nucleic acid probe

Locked nucleic acid (LNA) is a modified RNA nucleotide that can be incorporated at specific positions to generate probes with the desired length, melting temperature (T_M), and specificity. Here, we describe a method of multiplex genotyping based on dramatic shifts in the T_M of a single dual-labeled LNA probe. Using this method, two varieties of the hairtail fish Trichiurus lepturus can be distinguished from each other, as well as from Trichiurus japonicus, based on a 1- to 2-bp difference in a fragment of mitochondrial cytochrome oxidase subunit 1. The shift in T_M was 15 °C for a 1-bp mismatch and 27 °C for a 2-bp mismatch, indicating remarkable specificity. We anticipate that the method will be widely useful in applications such as species identification that require accurate, multiplex, and efficient detection of DNA polymorphisms.