Age determination and age related factors in the teeth of Western North Atlantic bottlenose dolphins.

Teeth were taken from 120 bottlenose dolphins, Tursiops truncatus, which had stranded on the mid-Atlantic coast of the United States. The number of annual growth layer groups (GLGs) for each animal was used to construct a growth curve. The growth rate of coastal North Atlantic Ocean Tursiops is similar to other cetaceans in having a high initial rate of growth, with no differences in growth between females and males. In females, the first dentinal GLG is thickest and is followed by GLGs which become progressively narrower. In males, the second GLG is thicker than the first; GLGs beyond number two become progressively smaller but at a slower rate than in females. In males and females, the translucent layer makes up proportionally larger parts of the GLG as the animal ages, but in males the percent translucent layer remains constant at about 50% while in females it continues to increase up to about 70% of the GLG. These two factors, GLGs width and translucent layer width, indicate that the sex and age of the animal influence the deposition of GLGs. Incremental layers are also present, averaging 12 per GLG, and seem similar to incremental layers described in other marine mammals. A plot of the relationship of percent growth of the last GLG to time of death suggests that the deposition of GLGs is relatively constant, at least during the first half of the year, and that North Atlantic Ocean Tursiops give birth in the fall as well as in the spring. (PDF contains 31 pages.

Determining Season of Death of Archaeological Fauna by Analysis of Teeth

Seasonality of site occupation is a common concern in northern archaeology, and any faunal remains recovered should be analysed in an attempt to provide data useful for its determination. Conclusions reached in the past on the subject of seasonality have been based on data concerning composition of species, age composition of mammalian remains based on tooth eruption or epiphyseal closure ages, or traits such as antler retention or loss in cervids. The present paper constitutes a report on the successful adaptation to archaeological samples of an ageing technique widely applied in wildlife management: the "reading" of annual growth layers in mammalian teeth. Since teeth are often the most common, and usually the most identifiable, faunal remains from archaeological sites, the information resulting from a judicial use of the technique should supplement data concerning seasonality gathered by other methods and act as an independent check against them

Guía para la determinación de la edad del ciervo ibérico (Cervus elaphus hispanicus) a través de su dentición: revisión metodológica y técnicas de elección

La determinación de la edad de los ciervos cazados es fundamental e imprescindible para valorar tanto la calidad individual como la calidad de la población en su conjunto y pone en perspectiva cuestiones sobre gestión y manejo. La determinación de la edad es la mejor fuente de información para evaluar los resultados de la gestión desarrollada, monitorizar el cumplimiento de los objetivos marcados a medio y largo plazo, y valorar las consecuencias de prácticas de manejo anteriores. También constituye una información básica imprescindible para realizar predicciones sobre el futuro demográfico de las poblaciones a gestionar, bien sea para incrementar su densidad o para limitarla. Y además, es necesario conocer la edad con el mayor detalle y precisión posibles cuando se investigan temas como crecimiento corporal, reproducción, supervivencia o longevidad. Este trabajo recopila los resultados más destacados de la puesta a punto de diversos métodos y técnicas de determinación de edad en el ciervo ibérico (Cervus elaphus hispanicus) del sur de España, a partir del estudio de ciervos cazados en Sierra Morena Oriental y de edad conocida. Se revisan antecedentes, y fundamentos metodológicos haciendo especial referencia a las técnicas esqueletocronológicas es decir, al uso de marcas de crecimiento en tejidos dentales evidenciadas mediante histología convencional o petrografía. Se discuten y explican las limitaciones y errores intrínsecos a cada método a modo de guía práctica para veterinarios, biólogos y gestores interesados.Aging of hunted deer is essential to evaluate both the individual quality and the quality of the population as a whole, and puts into perspective questions about management and handling. The age determination is the best source of information to evaluate the results of the management undertaken, to monitor the achievement of objectives developed both medium and long term and to evaluate the consequences of the practices of previous management. It also constitutes as basic essential information to make predictions about the demographic future of the populations to manage, whether to increase their density or to limit it. It is also necessary to know the age with the greatest detail and precision as possible when subjects such as body growth, condition, reproduction, survival or longevity are investigated. This paper collects the most outstanding results of various methods and techniques for determining the age of the Iberian Deer (Cervus elaphus hispanicus) in the south of Spain, from the study of deer hunted in Oriental Sierra Morena and of a known age. Background is reviewed and methodological fundamentals with special reference to skeletochronology, the use of marks of growth in dental tissues evident through conventional histology or petrography. The limitation and intrinsic error to each method are discussed and explained as a kind of practical guide for interested veterinary, biologists and managers

Comparison of age determination techniques for known-age Cape fur seals

Known-age teeth were used to validate age determination techniques for the Cape fur seal (Arctocephalus pusillus pusillus). Thin sectioning and staining of decalcified teeth produced the poorest age estimates. For etched half canines, only upper canines could be used to estimate age with good results, and coating improved the accuracy. Scanning electron microscopy produced poor accuracy in age estimation. External ridges reflected age accurately only in younger age classes and should only be used to verify counts of internal growth layer groups, or when rapid, preliminary estimates of age are necessary. This study has highlighted the importance of comparing different age determination techniques and validating such techniques with known-age anImals. The reliability with which age can be estimated for the Cape fur seal has also been improved.S. Afr. J. Zool. 1997,32(4

Dental pulp exposure, periapical inflammation and suppurative osteomyelitis of the jaws in juvenile Baltic grey seals (<i>Halichoerus grypus grypus</i>) from the late 19th century

<div><p>The systematic analysis of museum collections can provide important insights into the dental and skeletal pathology of wild mammals. Here we present a previously unreported type of dental defect and related skull pathology in five juvenile Baltic grey seals that had been collected in the course of a seal culling program along the Danish coast in 1889 and 1890. All five skulls exhibited openings into the pulp cavities at the crown tips of all (four animals) or two (one animal) canines as well as several incisors and (in one animal) also some anterior premolars. The affected teeth showed wide pulp cavities and thin dentin. Pulp exposure had caused infection, inflammation, and finally necrosis of the pulp. As was evidenced by the extensive radiolucency around the roots of the affected teeth, the inflammation had extended from the pulp into the periapical space, leading to apical periodontitis with extensive bone resorption. Further spreading of the inflammation into the surrounding bone regions had then caused suppurative osteomyelitis of the jaws. The postcanine teeth of the pathological individuals typically had dentin of normal thickness and, except for one specimen, did not exhibit pulp exposure. The condition may have been caused by a late onset of secondary and tertiary dentin formation that led to pulp exposure in anterior teeth exposed to intense wear. Future investigations could address a possible genetic causation of the condition in the studied grey seals.</p></div

Soundings: the Newsletter of the Monterey Bay Chapter of the American Cetacean Society. 2006

(PDF contains 88 pages.

Determinación de edades en Otariidae y Phocidae (Carnivora) sobre piezas dentarias, técnicas alternativas

The periodic depositing of layers of cement and dentine on the mammal’s teeth it is very useful to determine the absolute age. The different events produced during the life cycle as moult, sexual maturity, nursing and feeding are reflected on the amount and type of cement and dentine deposits on the teeth. The aim of this contribution is to determine through the application of different techniques the age of specimens of Phocidae and Otariidae (Mammalia) housed on different collections in Argentina; in order to compare the results obtained with the use of different techniques and to incorporate a crucial datum to each studied specimen. The different techniques were tested, improved and then were performed on 335 specimens of Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophagus e Hydrurga leptonyx. The techniques used were: root external rings counting, dentine and cement line counting, both undecalsified as decalsified. Our results showed that not all techniques are effective for all species and for all teeth, effectiveness depends i.e. on the teeth size,  on the way on the cement is deposited. Finally, we recommend which techniques are more effective for each species. The external ring and dentine line counting techniques with and without decalsification are more suitable for Arctocephalus, the dentine line counting by decalsification is recommendable for O. byronia, while in focids is better to used the line cements counting with previuos decalcificaction in postcanines.La depositación periódica de capas de esmalte, cemento y dentina en los dientes de los mamíferos es de gran utilidad para la determinación de edades absolutas. Los diferentes sucesos que se producen durante la vida del animal como la muda, la madurez sexual, período de lactancia y de alimentación, se reflejan muchas veces en la cantidad y tipo de depósito de dentina en las piezas dentarias. Los objetivos de este trabajo son: determinar, con diferentes técnicas aplicables sobre dientes, las edades absolutas de ejemplares de Phocidae y Otariidae (Mammalia) alojados en diferentes colecciones de la Argentina; comparar los resultados obtenidos con el empleo de las distintas técnicas; y añadir un dato relevante a cada ejemplar estudiado. Se compararon, ajustaron, y aplicaron las técnicas a un total de 335 ejemplares de las siguientes especies: Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophagus, e Hydrurga leptonyx. Las tecnicas aplicadas fueron: el conteo de anillos externos de la raíz, el conteo de líneas de dentina y de cemento tanto sin descalcificar como descalcificado. Los resultados mostraron que no todas las técnicas son aplicables a todas las especies, ni para todas las piezas dentarias, dependiendo en parte del tamaño de las piezas y de la forma en que el cemento se deposita. Finalmente recomendamos cuáles técnicas son más efectivas para cada especie estudiada. La técnica de conteo de anillos externos y lineas de dentina con y sin descalcificación es conveniente para los Arctocephalus, mientras que la del conteo de líneas de dentina por descalcificación es recomendable para O. byronia, en los fócidos se recomienda el conteo de líneas de cemento con previa descalcificación en poscaninos

Age determination on teeth of Otariidae and Phocidae (Carnivora), alternative techniques

La depositación periódica de capas de esmalte, cemento y dentina en los dientes de los mamíferos es de gran utilidad para la determinación de edades absolutas. Los diferentes sucesos que se producen durante la vida del animal como la muda, la madurez sexual, período de lactancia y de alimentación, se reflejan muchas veces en la cantidad y tipo de depósito de dentina en las piezas dentarias. Los objetivos de este trabajo son: determinar, con diferentes técnicas aplicables sobre dientes, las edades absolutas de ejemplares de Phocidae y Otariidae (Mammalia) alojados en diferentes colecciones de la Argentina; comparar los resultados obtenidos con el empleo de las distintas técnicas; y añadir un dato relevante a cada ejemplar estudiado. Se compararon, ajustaron, y aplicaron las técnicas a un total de 335 ejemplares de las siguientes especies: Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophaga, e Hydrurga leptonyx. Las tecnicas aplicadas fueron: el conteo de anillos externos de la raíz y el conteo de líneas de dentina y de cemento tanto sin descalcificar como descalcificado. Los resultados mostraron que no todas las técnicas son aplicables a todas las especies, ni para todas las piezas dentarias, dependiendo en parte del tamaño de las piezas y de la forma en que el cemento se deposita. Finalmente, recomendamos cuáles técnicas son más efectivas para cada especie estudiada. La técnica de conteo de anillos externos y lineas de dentina con y sin descalcificación es conveniente para las especies de Arctocephalus estudiadas, mientras que la del conteo de líneas de dentina por descalcificación es recomendable para O. byronia. Para las especies de fócidos analizadas se recomienda el conteo de líneas de cemento con previa descalcificación en poscaninos.The periodic depositing of layers of cement and dentine on the mammal’s teeth it is very useful to determine the absolute age. The different events produced during the life cycle as moult, sexual maturity, nursing and feeding are reflected on the amount and type of cement and dentine deposits on the teeth. The aim of this contribution is to determine through the application of different techniques the age of specimens of Phocidae and Otariidae (Mammalia) housed on different collections in Argentina; in order to compare the results obtained with the use of different techniques and to incorporate a crucial datum to each studied specimen. The different techniques were tested, improved and then were performed on 335 specimens of Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophaga e Hydrurga leptonyx. The techniques used were: root external rings counting and dentine and cement line counting, both undecalsified as decalsified. Our results showed that not all techniques are effective for all species and for all teeth, effectiveness depends i.e. on the teeth size, on the way on the cement is deposited. Finally, we recommend which techniques are more effective for each species. The external ring and dentine line counting techniques with and without decalsification are more suitable for Arctocephalus, the dentine line counting by decalsification is recommendable for O. byronia. In focids is better to used the line cements counting with previuos decalcificaction in postcanines.Facultad de Ciencias Naturales y Muse

Age determination on teeth of Otariidae and Phocidae (Carnivora), alternative techniques

La depositación periódica de capas de esmalte, cemento y dentina en los dientes de los mamíferos es de gran utilidad para la determinación de edades absolutas. Los diferentes sucesos que se producen durante la vida del animal como la muda, la madurez sexual, período de lactancia y de alimentación, se reflejan muchas veces en la cantidad y tipo de depósito de dentina en las piezas dentarias. Los objetivos de este trabajo son: determinar, con diferentes técnicas aplicables sobre dientes, las edades absolutas de ejemplares de Phocidae y Otariidae (Mammalia) alojados en diferentes colecciones de la Argentina; comparar los resultados obtenidos con el empleo de las distintas técnicas; y añadir un dato relevante a cada ejemplar estudiado. Se compararon, ajustaron, y aplicaron las técnicas a un total de 335 ejemplares de las siguientes especies: Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophaga, e Hydrurga leptonyx. Las tecnicas aplicadas fueron: el conteo de anillos externos de la raíz y el conteo de líneas de dentina y de cemento tanto sin descalcificar como descalcificado. Los resultados mostraron que no todas las técnicas son aplicables a todas las especies, ni para todas las piezas dentarias, dependiendo en parte del tamaño de las piezas y de la forma en que el cemento se deposita. Finalmente, recomendamos cuáles técnicas son más efectivas para cada especie estudiada. La técnica de conteo de anillos externos y lineas de dentina con y sin descalcificación es conveniente para las especies de Arctocephalus estudiadas, mientras que la del conteo de líneas de dentina por descalcificación es recomendable para O. byronia. Para las especies de fócidos analizadas se recomienda el conteo de líneas de cemento con previa descalcificación en poscaninos.The periodic depositing of layers of cement and dentine on the mammal’s teeth it is very useful to determine the absolute age. The different events produced during the life cycle as moult, sexual maturity, nursing and feeding are reflected on the amount and type of cement and dentine deposits on the teeth. The aim of this contribution is to determine through the application of different techniques the age of specimens of Phocidae and Otariidae (Mammalia) housed on different collections in Argentina; in order to compare the results obtained with the use of different techniques and to incorporate a crucial datum to each studied specimen. The different techniques were tested, improved and then were performed on 335 specimens of Arctocephalus gazella, Arctocephalus australis, Otaria byronia, Mirounga leonina, Leptonychotes weddellii, Lobodon carcinophaga e Hydrurga leptonyx. The techniques used were: root external rings counting and dentine and cement line counting, both undecalsified as decalsified. Our results showed that not all techniques are effective for all species and for all teeth, effectiveness depends i.e. on the teeth size, on the way on the cement is deposited. Finally, we recommend which techniques are more effective for each species. The external ring and dentine line counting techniques with and without decalsification are more suitable for Arctocephalus, the dentine line counting by decalsification is recommendable for O. byronia. In focids is better to used the line cements counting with previuos decalcificaction in postcanines.Fil: Loza, Cleopatra Mara. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Soibelzon, Leopoldo Héctor. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Tarnawski, Bárbara Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: del Corro, M. E.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Negrete, Javier. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ciancio, Martin Ricardo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin