منابع مشابه
Genetic rediscovery of an ‘extinct’ Galápagos giant tortoise species
their sperm. As mentioned above, if sperm were not adapted to survive (sperm longevity) inside the female’s reproductive tract, the female would be limited in her ability to maintain sperm. Males may face a trade-off between sperm competitive ability (fast-swimming sperm) and ability to be stored (long-lived and slow-swimming sperm). Sperm pre-adaptations for storage include a decreased sensiti...
متن کاملStratigraphy and Phylogeny of the Giant Extinct Rat Kangaroos
The Giant Rat-kangaroos were placed in the Propleopinae by Archer & F\annery (1985) and in the Hypsiprymnodontidae by Ride (1993). Cladistic analysis of Ekaltadeta material from Riversleigh, northwestern Queensland (Wroe, 1996) suggested that a middle to late Miocene dichotomy in Ekaltadeta may have produced two lineages of Plio-Pleistocene Propleopus. indicating polyphyly for Propleopus and pa...
متن کاملLocomotion in Extinct Giant Kangaroos: Were Sthenurines Hop-Less Monsters?
Sthenurine kangaroos (Marsupialia, Diprotodontia, Macropodoidea) were an extinct subfamily within the family Macropodidae (kangaroos and rat-kangaroos). These "short-faced browsers" first appeared in the middle Miocene, and radiated in the Plio-Pleistocene into a diversity of mostly large-bodied forms, more robust than extant forms in their build. The largest (Procoptodon goliah) had an estimat...
متن کاملAncient DNA from giant extinct lemurs confirms single origin of Malagasy primates.
The living Malagasy lemurs constitute a spectacular radiation of >50 species that are believed to have evolved from a common ancestor that colonized Madagascar in the early Tertiary period. Yet, at least 15 additional Malagasy primate species, some of which were relative giants, succumbed to extinction within the past 2,000 years. Their existence in Madagascar is recorded predominantly in its H...
متن کاملAncient Nursery Area for the Extinct Giant Shark Megalodon from the Miocene of Panama
BACKGROUND As we know from modern species, nursery areas are essential shark habitats for vulnerable young. Nurseries are typically highly productive, shallow-water habitats that are characterized by the presence of juveniles and neonates. It has been suggested that in these areas, sharks can find ample food resources and protection from predators. Based on the fossil record, we know that the e...
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ژورنال
عنوان ژورنال: Proceedings of the Royal Society of London. Series B: Biological Sciences
سال: 2001
ISSN: 0962-8452,1471-2954
DOI: 10.1098/rspb.2001.1743