Aria Productions
Welcome!


Welcome to Aria Productions forum...One of the best clans and video makers in the world!
 
HomeCalendarFAQRegisterLog in

Share | 
 

 A hypothesis

View previous topic View next topic Go down 
AuthorMessage
wangrong
Haxxor
Haxxor


Posts : 213
Join date : 2010-10-11

PostSubject: A hypothesis   Fri Feb 11, 2011 7:48 am

A hypothesis of Albertosaurus life history postulates that hatchlings died in large numbers, but have not been preserved in the fossil record due to their small size and fragile construction. After just two years, juveniles were larger than any other predator in the region aside from adult Albertosaurus, and more fleet of foot than most of their prey animals. This resulted in a dramatic decrease in their mortality rate and a corresponding rarity of fossil remains. Mortality rates doubled at age twelve, perhaps the result of the physiological demands of the rapid growth phase, and then doubled again with the onset of sexual maturity between the ages of fourteen and sixteen. This elevated mortality rate continued throughout adulthood, perhaps due to high physiological demands, stress and injuries received during intraspecific competition for mates and resources, and eventually, the ever-increasing effects of senescence. The higher mortality rate in adults may explain their more common preservation. Very large animals were rare because few individuals survived long enough to attain such sizes. High infant mortality rates, followed by reduced mortality among juveniles and a sudden increase in mortality after sexual maturity, with very few animals reaching maximum size, is a pattern observed in many modern large mammals, including elephants, African buffalo, and rhinoceros. The same pattern is also seen in other tyrannosaurids. The comparison with modern animals and other tyrannosaurids lends support to this life history hypothesis, but bias in the fossil record may still play a large role, especially since more than two-thirds of all Albertosaurus specimens are known from one locality.[3][18]


medical uniform
cheap plane tickets
Back to top Go down
 
A hypothesis
View previous topic View next topic Back to top 
Page 1 of 1

Permissions in this forum:You cannot reply to topics in this forum
Aria Productions :: Fun stuff! :: Forum Games-
Jump to: