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1.
Erythrocebus patas has a short inter-birth interval, juveniles become independent from their mother early, females are young at first birth,
and adult females have a high mortality rate. According to Schultz’s rule, the molars of fast-growing and shorter-lived primate
species erupt early relative to the replacement teeth. Based on the life history of E. patas, we hypothesized that the molars would erupt before the replacement teeth and/or that the eruption time of its molars would
be early. The purpose of the present study was to determine the dental eruption sequence and eruption times for E. patas and to test our hypothesis. The eruption sequence for the permanent teeth of E. patas is
\frac\textM1 \textI1 \textI2 \textM2 \textP3 \textP4 [\textC \textM3]\textM1 \textI1 \textI2 \textM2 \textP4 [\textP3 \textC]\textM3 \frac{{{\text{M1}}\;{\text{I1}}\;{\text{I2}}\;{\text{M2}}\;{\text{P3}}\;{\text{P4}}\;[{\text{C}}\;{\text{M3}}]}}{{{\text{M1}}\;{\text{I1}}\;{\text{I2}}\;{\text{M2}}\;{\text{P4}}\;[{\text{P3}}\;{\text{C}}]{\text{M3}}}} in males and
\frac\textM1 \textI1 \textI2 [\textM2 \textP4 \textP3 \textC]\textM3\textM1 \textI1 \textI2 [\textM2 \textP4 \textP3 \textC]\textM3 \frac{{{\text{M1}}\;{\text{I1}}\;{\text{I2}}\;[{\text{M2}}\;{\text{P4}}\;{\text{P3}}\;{\text{C}}]{\text{M3}}}}{{{\text{M1}}\;{\text{I1}}\;{\text{I2}}\;[{\text{M2}}\;{\text{P4}}\;{\text{P3}}\;{\text{C}}]{\text{M3}}}} in females. Because these sequences constitute the general pattern seen in cercopithecines, Schultz’s rule could not be applied
to E. patas. The emergence time of upper and lower first molar (M1) is earlier in E. patas than in macaques, baboons, and mandrills and is similar to that in Chlorocebus aethiops. The emergence time of deciduous upper and lower fourth premolar (dp4) is similar to that in the above-mentioned cercopithecines
but is later than that in Ch. aethiops. The emergence times of upper and lower second molar (M2) and upper and lower third molar (M3) in E. patas are earlier than those in the above-mentioned cercopithecines but later than those in Ch. aethiops. However, the intervals of the emergence time between each permanent molar in E. patas are similar to those of the above-mentioned cercopithecines. The early appearance of M2 and M3 in E. patas is related to the short interval of emergence time between dp4 and M1. 相似文献
2.
We investigated the state of dental eruption in specimens of Macroscelides proboscideus and Erinaceus europaeus of known age. When M. proboscideus reaches adult size and sexual maturity, few or none of its replaced permanent cheek teeth have erupted. The approximate sequence
of upper tooth eruption is P1, [I3, C, M1], [I1–2], M2, P4, [P2, P3]. Chronologically, E. europaeus erupts its molars and most premolars prior to M. proboscideus; but its first two upper incisors erupt after those of M. proboscideus, and its canines erupt around the same time. The approximate sequence of upper tooth eruption in E. europaeus is [M1, M2, P2, I3], C, M3, P4, P3, I2, I1. Unlike M. proboscideus, E. europaeus does not reach adult size until all permanent teeth except for the anterior incisors have erupted. While not unique among
mammals, the attainment of adult body size prior to complete eruption of the permanent cheek teeth is particularly common
among macroscelidids and other afrotherians. 相似文献
3.
Robert H. Eaglen 《American journal of physical anthropology》1985,66(3):307-315
Observations on the sequence and timing of gingival tooth eruption are reported for six species of Madagascar lemurs. Complete sequences of eruption were obtained for the deciduous dentition, and partial to complete sequences were recorded for the permanent dentition. In Cheirogaleus medius and in four species of the genus Lemur, the deciduous teeth erupt in front-to-back sequence, with the toothcomb emerging near birth as an integrated complex. In Propithecus verreauxi the same pattern is exhibited, but the small peglike lower canine and dp3 erupt last. Eruption of the permanent dentition in Lemur species takes place in two distinct stages. In the first stage the upper incisors, toothcomb, and first two molars penetrate the gingiva. After an interval of 3 to 4 months, the remaining permanent teeth erupt. Deciduous premolars erupt when young animals are being weaned. The eruption of the deciduous toothcomb appears unrelated to feeding or grooming behavior. In L. catta and L. fulvus, the first stage of permanent tooth eruption occurs at approximately 6 months of age, when the growth rate slows down and (in wild populations) the rainy season is ending. This suggests that eruption of the anterior molars is timed to coincide with a shift from a more frugivorous to a more folivorous dietary regime, which occurs during the dry season. No further tooth eruption occurs until approximately 1 year of age, when the growth rate increases and the rainy season returns for wild populations. Thus, the second wave of permanent tooth eruption in these species again appears linked to changing climatic conditions which lead to a shift in dietary preferences. 相似文献
4.
Thomas Martin 《Journal of Mammalian Evolution》1997,4(1):1-18
The discovery of juvenile dentitions of late Jurassic (Kimmeridgian) Dryolestidae (Eupantotheria, Mammalia) from Guimarota, Portugal, yields for the first time information on the mode of tooth replacement in therian mammals prior to the dichotomy of placentals and marsupials. As in extant placentals, tooth replacement occurs at all antemolar positions [incisors (I1–I4), canine (C), premolars (P1–P4)]. P1 and P2 have premolariform milk predecessors, whereas the large premolariform third (P3) and fourth premolars (P4) are preceded by molariform deciduous premolars (dP3, dP4). Tooth replacement takes place in two waves, at least in the lower jaw, with I2, I4, P1, and P3 in the first series and I1, I3, C, P2, and P4 in the second. P4 is the last premolar to erupt, and it is present when the sixth molar (M6) starts to break through. The reduced tooth replacement pattern of marsupials (with only dP3 being replaced postnatally) evolved secondarily from the primitive or plesiomorphic mammalian condition, which was retained in Dryolestidae and Eutheria. 相似文献
5.
Microevolutionary trends in dental traits were studied in a Polish population of the Red fox, Vulpes vulpes (Linnaeus, 1758). Changes in qualitative and quantitative traits over a 70‐year interval were analysed in 1453 museum specimens collected between 1927 and 1996. Over that period, there were qualitative trends towards increasing complication of occlusal crown surface in posterior premolars (i.e. P4, P3, P4) and I3. Other cheek teeth did not undergo directional change. Changes in trait correlations were assessed using samples from the 1960s and 1990s. The correlations between C1–C1 and M1–M2 increased, while correlation values in the incisor region (I1–I2, I1–I1, I1–I2, I3–I2), carnassial region (P4–M1, P4–M1 and M1–M1) and in P2–P1 decreased. These changes may be related to increasing dietary opportunism of the Red fox during the 20th century. 相似文献
6.
L. A. Winkler J. H. Schwartz D. R. Swindler 《American journal of physical anthropology》1996,99(1):205-220
This study examines dental formation and alveolar emergence in a large cross-sectional sample composed primarily of wild-reared orangutans (N = 89) in order to provide information on the development of the permanent dentition in this hominoid and to address questions of variation in individual tooth formation, between teeth and between individuals. All specimens have been radiographed in lateral aspect and stages of crown and root formation recorded for all teeth. The ranges of crown and root formation of I11, C11, P44, and M33 have been calculated relative to the stage of M11 development within a specific tooth quadrant. Then, for each specimen, BMDP scatterplot and nonparametric statistics have been used to graph changes in stages of these teeth relative to M11 stages and to examine relationships between pairs of upper and lower dental counterparts and between teeth of each jaw. Results indicate 1) high correlations between upper and lower tooth pairs and between many of the permanent teeth within individuals, 2) a relatively large range of variability in individual tooth development (multistage ranges relative to M11), 3) greater variation in root development at emergence than earlier reports, and 4) evidence of variability within the sequence emergence pattern of the orangutan. © 1996 Wiley-Liss, Inc. 相似文献
7.
Pan Yuerong 《Human Evolution》1990,5(3):239-240
The paper deals with a new form ofSinoadapis from the Lufeng hominoid Locality, assigned toSinoadapis shihuibaensis sp. nov. Holotype PA 882 A fragment of right mandible with C,−M3. Other materials. PA 903 A fragment of left maxilla with P3−M3. PA 959 Left lower tooth row with I1−P2, P4. PA 902 Right upper tooth row with C′−P3. PA 964 An isolated left I1. PA 907 An isolated right I3. PA 972 An isolated right M3. 相似文献
8.
Jerry Hooker 《Historical Biology》2018,30(1-2):42-52
AbstractThe 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 P2–3 in size and their roots from two to one. 相似文献
9.
Two genera and three species of adapid primates are known from the middle and late Miocene of India and Pakistan. Most fossil
specimens are fragmentary, but the best-known species, Sivaladapis nagrii,is now represented by enough specimens to permit composite reconstruction of much of the dentition. The incisors of Sivaladapishave spatulate crowns, and the canines are large, projecting teeth. Premolars and molars exhibit complex occlusion involving
simultaneous approximation of pointed leading cusps on upper and lower molars, with linear trailing lophs. The premolar eruption
sequence in Sivaladapisappears to be P
2-P4-P3, as in most extant prosimians. Symphyseal fusion of the mandibular rami occurred early in ontogeny, before the eruption of
any of the anterior permanent teeth. We interpret Sivaladapisto have been a specialized arboreal folivore that became extinct near the end of the Miocene, when the distribution of forests
was increasingly restricted and colobine monkeys first invaded South Asia. 相似文献
10.
Isotopic and genetic analyses of a mass grave in central California: Implications for precontact hunter‐gatherer warfare
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Jelmer W. Eerkens Traci Carlson Ripan S. Malhi Jennifer Blake Eric J. Bartelink Gry H. Barfod Alan Estes Ramona Garibay Justin Glessner Alexandra M. Greenwald Kari Lentz Hongjie Li Charla K. Marshall 《American journal of physical anthropology》2016,159(1):116-125
11.
Carlos A. Galliari 《Primates; journal of primatology》1985,26(4):506-510
This work reports on the ages of gingival eruption of deciduous and permanent teeth observed from the time of birth until
30 months old, captive-born individuals.
All of the animals were born with the protrusive di1 already through the gingival border. The dmp4 were the last teeth of the deciduous series which emerged at 24.5±3.11 weeks in the males and 27.8±2.95 weeks in the females.
Significant sexual differences were found between the eruption period of the dpm2, dmp4 (p<0.05), and dpm4 (p<0.01), with the males being more precocious than the females.
The first permanent tooth that emerged, usually, was the M1 at 13.50±2.12 months in the males, and 14.00±0.82 months in the females. At 30 months of age, not one individual had replaced
his deciduous canine or premolar teeth with the permanent ones, and, moreover, the M
3
3
had not yet emerged. 相似文献
12.
Previous studies on tooth replacement in lower vertebrates have been plagued by a lack of common integrative approaches and methods, making it impossible to furnish a phylogenetic synthesis. This study is based on serial sections of the jaw of Prionurus microlepidotus. Each Toothgerm was characterized by its developmental stage and its position in the jaw. The relationship between the developmental stage of toothgerm and position in the jaw has been studied and expressed in several graphical illustrations. The following conclusions have been made: (1) The initiation of toothgerms in P. microlepidotus is governed by two Zahnreihen, which respectively initiate toothgerms on the lingual and labial side of the functioning teeth in an alternating pattern. (2) Therefore, functioning teeth in one locus are supplied by the alternate eruption of lingual and labial toothgerms. (3) Advancing of tooth replacement in each locus is independent of functioning teeth and their successors in adjacent loci. (4) The disorders of replacement patterns are caused by an alternated rate of eruption of successive toothgerms as a response to unusual shedding of the functioning teeth. 相似文献
13.
Dental abnormalities including polydonty, oligodonty, extra roots, different root morphotype, root fusion, different crown
morphotype, crown reduction, partial crown eruption, supernumerary cusp, irregularities in the position of the teeth, and
malocclusion were studied in a set of 785 red foxVulpes vulpes (Linnaeus, 1758) skulls (401 males, 273 females, and 111 individuals of unknown sex) from the Czech Republic. Three hundred
sixty one cases of deviations from normal were found in 170 specimens (21.7%). Most of the deviations were variants within
a genetically determined range. The prevalent dental variants included an extra root of M1 (5.7% specimens), and different root morphotype of P1 (1.9% specimens). On the other hand, the real dental anomalies, eg polydonty, occurred seldom within the population. P1
1 and M3 were missing significantly more frequently among females than among males unlike the other deviations, which were divided
equally between the sexes. No differences were found between the left and right side of the jaw. Irregularities in the position
of the teeth and oligodonty (excluding P1
1, M3) appeared significantly more abundantly on mandible, whereas extra roots and polydonty were more common on the maxilla. There
was no relationship between the incidence of dental abnormalities and the relative mandible and rostrum length. 相似文献
14.
M L Ajmani S P Jain S D Joshi 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》1986,44(2):143-148
An attempt has been made to estimate the eruption age of wisdom teeth in the North Nigerian population. The present study was carried out on 654 boys and 584 girls of age groups ranging from 11-23 years. From the data collected estimates have been provided for the eruption age of the third molar. In general, teeth of the lower jaw erupt before those of the upper jaw. The teeth on the left side erupt earlier than those on the right side. The wisdom teeth erupt little earlier amongst boys (18 years) as compared with girls (18.5 years). In general, the wisdom teeth erupt in Nigerians with some constancy between the age of 15 and 21. The wisdom teeth fail to erupt in 5% of the individuals. 相似文献
15.
Wendy A. Lawrence Anthony M. Coelho John H. Relethford 《American journal of primatology》1982,2(3):295-300
A detailed eruption sequence and associated age of eruption for deciduous dentition in baboons (Papio sp) are presented in this paper. The sequence was determined by evaluation and comparison of the number and kinds of teeth present in nine age cohorts comprising the study sample of 88 males and 87 females who ranged in age from birth to 763 days. Eruption was assessed visually as present or absent. Several statistical methods used to derive the ages associated with the eruption sequence are described. The basic eruption sequence in the sample population is: i1 i1, i2, i2, \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {\rm c}\limits_{\rm -} {\rm,}\mathop {\rm c}\limits^{\rm -} $\end{document} m1 (m2, m2), M1, M1. Both sexes show the same pattern, with the exception of the second deciduous molar, where males show a sequence of m2, m2, while females show the opposite. Posterior dentition shows the greatest gender-specific variation in average age of eruption. 相似文献
16.
Anna Maria De Marinis Roberta Chirichella Elisa Bottero Marco Apollonio 《European Journal of Wildlife Research》2018,64(4):50
Increasing evidence suggests that conditions in early life have important consequences for body size and fitness in mammals. As regards herbivores, teeth play a central role in the long-term performance of individuals. So far, however, patterns of teeth eruption have been scarcely investigated in relation to environmental and climatic factors experienced by herbivores. We described the eruption timing of mandibular teeth in a population of roe deer (Capreolus capreolus) located in the Apennines (Central Italy), through the analysis of 2161 jaws of fawns (1176 females and 985 males) shot in their first winter of life over three hunting seasons (2013–2015). Results showed that the percentage of juveniles exhibiting permanent teeth depends on the cohort. Among the factors that may affect both incisiviform and molariform teeth replacement timing, our findings include body mass and population density. Additional factors determining the relative speed of teeth replacement are (1) food availability for the mother during the last part of gestation, the birth period and the lactation, (2) winter temperature experienced by the mother, and (3) temperature experienced by fawns during their first summer and autumn. Besides, for the first time in literature, elevation was reported to delay front teeth replacement. A greater number of climatic factors were found to shape the eruption timing of the third molar (M3) in comparison to that of incisiviform teeth. Also, a different pattern was found in males and females. The eruption of M3 is, indeed, a costly and long-lasting process requesting optimal nutritional conditions and the meeting of a threshold jaw size. Our results indicate a strong correlation between environmental conditions and eruption process, i.e., between resource availability during the gestation and rearing periods and eruption timing. 相似文献
17.
Dental variation in the Chinese golden monkey (Rhinopithecus roxellana) is here evaluated by univariate, bivariate, and multivariate analyses. Allometric analyses indicate that canines and P3s
are positively, but other dimensions negatively scaled to mandible and maxilla, and to body size. With the exception of the
mesiodistal dimensions of I1 and M3, and the buccolingual dimension of P4, mandibular dental variables show similar scaling relative to body size. Analysis of residuals shows that males have significantly
larger canine, P3 and buccolingual dimensions of the postcanine teeth (M2 and M3) than females. A significant difference in shape between the sexes is found in the buccolingual dimension of the upper teeth,
but not in the mandible. Unlike the situation in some other species, female golden monkeys do not exhibit relatively larger
postcanine teeth than males. In fact, the reverse is true, expecially for M2s and M3s. The fact that most of the dental variables show low negative allometry to body size might be related a cold environment
that has led to the development of larger body size with reduced energy loss. When the raw data are examined by Discriminant
Function Analysis the sexes are clearly distinguishable. 相似文献
18.
Tooth eruption sequences vary in a non-random way among mammalian species. Several variables have been linked to this, including tooth and jaw shape, adaptations to diet, and food processing. Likewise, changes in eruption patterns correlate with the speed of postnatal growth in some groups, the Schultz’s Rule pattern. Here, the eruption pattern of the permanent dentition in lower jaws from different cervid species have been investigated to discern the effect of these factors and phylogeny as well as to reconstruct the ancestral tooth eruption sequence of cervids. In ruminants, the different patterns of emergence of permanent teeth seem to be best explained by phylogeny. The degree of hypsodonty, age of first molar eruption, and life history parameters such as longevity and age of female sexual maturity do not explain the observed sequential differences in eruption patterns. The Parsimov-based analysis for the ancestral state resulted in a tooth eruption sequence of m1 – m2 – i1 – i2 – i3 – c – m3 – (ppp) for Cervidae; a pattern recorded in Odocoileus, Capreolus, and Hydropotes. The eruption pattern of Caenomeryx filholi, from the Oligocene of Gaimersheim, is identical to the result of the Parsimov-based analysis except for the presence of a first premolar, a tooth lost in cervids. 相似文献
19.
Egi N Takai M Tsubamoto T Maung Maung Chit Sein Shigehara N 《Primates; journal of primatology》2006,47(2):123-130
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 M2–3. 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. 相似文献
20.
Haowen Tong 《Geobios》2005,38(1):139
Most of the Quaternary tapir fossils from China are isolated teeth. The purpose of this paper is to identify them and to extract systematic and evolutionary information from them. Based on morphology and W/L ratio, isolated teeth can be identified successfully. On the whole, the identification of P1, M3 and P2 is believed to be reliable, while it is difficult to distinguish P3 from P4, M1 from M2 etc. Concerning the variations of the teeth, P1 is the most variable one in dimension. In the Quaternary tapirs in China, some dental characters can be used as reliable indicators to evaluate their evolutionary levels. The degree of the atrophy of the upper canine relative to the caniniform I3 is reflected in the C/I3 diameter ratio, which is decreasing during evolution. P1 changes considerably in outline and strength of the hypocone. Some forms are without hypocone, such as Tapirus sanyuanensis, some have a very faint hypocone, such as Tapirus indicus; although most of them show a developed hypocone. For other cheek teeth, the W/L ratio is decreasing through geologic time. Two lineages can be tentatively proposed: one is the Tapirus peii-Tapirus sinensis-Megatapirus augustus progression; the other is the T. sanyuanensis-T. indicus lineage. T. sanyuanensis and T. peii stand on the base, and it is very probable that the latter is more primitive. 相似文献