Выдержка (форум) профиля ......





Kurten (1966, 1967) recognized two genera and at least seven species of short-faced Pleistocene bears, subfamily Tremarctinae: the Neotropical Tremarctos ornatus (the only living species); T. floridanus, Arctodus pristinus, and A. simus from North America; and A. bonariensis, A. pamparus, and A. brasiliensis from South America. Other poorly known species from South America include Arctodus enectum (Paula Couto, 1960) and A. angustidens (Kragiievich, 1926). Several genera were created for the American fossil bears (see Kraglievich, 1926, and Kurten, 1966, 1967, for taxonomic revision). For instance, Paulo Couto recognized two genera (Paula Couto, 1960) or subgenera (Paula Couto, 1979) of South American extinct bears, Arctotherium and Pararctotherium, the latter including Arctodus brasiliensis. Kurten (1967) considered all tremarctine genera, except Tremarctos, as junior synonyms of Arctodus.


Kurten's classification was followed by Perea and Ubilla (1983, 1985), who distinguished two morphological patterns in the extinct genus Arctodus: pattern "G" (large forms) and pattern "P" (small forms). They assigned A. brasiliensis, with some restrictions, to pattern "P," characterized by inflated frontal region and auditory bullae, U -shaped postpalatine margin, lateral margin of mesopterygoid fossa independent from the styloid apophysis, and foramen rotundum emerging in the orbit independent of the alisphenoid canal.


A. brasiliensis, and represents a considerable extension to the northeast of the geographic range of South American tremarctines. The bear from Ubajara is compared to the known species of Tremarctinae, and its systematic position is discussed. A phylogenetic hypothesis of the genera of Tremarctinae is presented. We recognize Arctotherium as a separate genus, including the extinct South American tremarctines, with two subgenera: Arctotherium and Pararctotherium.





SOUTH AMERICA OVERVIEW


    * The bear from Ubajara is classified as A. (P.) brasiliense (comb. nov.).

    * The measurements of the Ubajara skull, mandible, and teeth are presented as well as those of other specimens previously assigned to A. brasiliense.

    * The differences in size and proportions between these specimens and the closely related A. pamparum and A. bonariense can be appreciated in the ratio diagrams.

    * No major qualitative differences between the specimen from Ubajara and those previously assigned to A. brasiliense from Minas Gerais State were found.



Если позволит время, я надеюсь (ожидать), чтобы добавить еще к этому профилю.

ИМХО, не стоит после каждого предложения ссылаться на Барышникова. Проще в конце дать список литературы и включить туда книгу Барышникова.

Статья готова - http://crazy-zoologist.livejournal.com/514625.html

http://mikrourl.eu/vvk

Отредактировано Wladimir (03 August 2010 17:26:34)

Владимир, а что за странные клыки у медведя на вашей фотке?


Ursus maritimus tyrannus was a very large fossil subspecies of the polar bear that descended from an Arctic population of brown bears. Its name in Latin means Tyrant Sea Bear.

Evolution
Ursus maritimus tyrannus was the first polar bear and evolved sometime in the mid-Pleistocene. While the oldest fossil is 100,000 years old, they are thought to have evolved between 100,000 and 250,000 years ago from a population of brown bears likely isolated by glaciation. That population is believed to have diminished in numbers quickly into a much smaller population selected by species individual variation who adapted better to the changed environment. Over time with intense selective pressures on a small population they evolved the characteristics of the first polar bears.

Appearance
Initially the isolated brown bears were no different than the variations of brown bears of that time period. Because litters of cubs can show significant species variations in hair color and hair thickness, this gave certain individuals a survival advantage passed on each generation. Eventually skull changes and even changes in dentition occurred leading to the smooth and rather quick evolution of U. maritimus tyrannus.

U. maritimus tyrannus was considerably larger then its modern relative. If everything is scaled out correctly from its remains, it would had been 183 cm (6 ft) at the shoulders, 3,6 m (12 ft) long and would have weighted an average of 1.2 tons, making it the largest bear "and one of the largest mammalian carnivores to ever walk on land". Its tremendous size makes it even bigger than the other "largest" mammalian carnivores that ever lived, including Andrewsarchus, Agriotherium, and Arctodus simus. It's speculated that this gigantic bear would, due to its formidable size and strength, have preyed on mammoths which also lived during the time

Я ничего не понял, там всё на французском.
А клыки какие-то чересчур длинные и "новенькие", как будто приделаны черепу.

В пределах десяти евро отыскать можно. А по трудам - конкретно на сборник не натыкался, лучше всего в "Гугле" поискать по статьям. Но профессор Г. Рабедер не только о медведях писал.

Интересно, он трескал моллюсков и ракообразных? Для ловли рыбы прыть нужна.

Отредактировано Revs (02 December 2010 00:07:23)

Revs :

Интересно, он трескал моллюсков и ракообразных? Для ловли рыбы прыть нужна.

Скорей всего, да. Коренные зубы у колпонома давящие, как раз могли предназначаться для поедания моллюсков, морских ежей, ракообразных. Фаланги и метоподии уплощенные, как это имеет место быть у ластоногих - так что колпономы вполне могли нырять и плавать, "ощипывая" вот так мидиевые банкив прибрежной зоне.

Ergaster :

Мы в свое время обсуждали интересного "медведя" - колпономоса, очевидно ведущего полуводный/околоводный  образ жизни. Хорошо иллюстрирует предполагаемый образ жизни картинко:
http://s013.radikal.ru/i324/1012/32/7e1c1089d8f6t.jpg

Михаил, образ жизни может и хорошо показан, но сам зверь какой-то неудачный, ИМХО. Мне кажется, что у него должен быть большой нос и густые вибриссы предполагаются.

Попадалась инфа в книгах, но отдельной статьи не видел. На русском даже у Барышникова есть.