Unfortunately this question is incomplete as no options are provided. IN actual fact,<span> four muscles are involved in mastication. Three of these are responsible for biting down, namely the masseter, the temporalis and the medial pterygoid, whereas one, the lateral pterygoid, is responsible for opening of the jaw</span><span>. All four muscles help to move the jaw laterally.</span>
These animals were living in an environment with a warm climate that results in changing sea levels. These conditions create a lot of shallow inland seas allowing these animals to thrive. The Cretaceous period is the last period of the Mesozoic area where new groups of mammals, birds, and flowering plants appeared on Earth.
Answer:
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ANIMALSPHOTO ARK
Grizzly bear
Grizzly bears once lived across much of western North America until European settlements and aggressive hunting eliminated most of the population.
PHOTOGRAPH BY JOEL SARTORE, NATIONAL GEOGRAPHIC PHOTO ARK
COMMON NAME: Grizzly bears
SCIENTIFIC NAME: Ursus arctos horribilis
TYPE: Mammals
DIET: Omnivore
AVERAGE LIFE SPAN IN THE WILD: 25 years
SIZE: Five to eight feet
WEIGHT: 800 pounds
SIZE RELATIVE TO A 6-FT MAN:
IUCN RED LIST STATUS:? Least concern
LC
NT
VU
EN
CR
EW
EX
LEAST CONCERN
EXTINCT
CURRENT POPULATION TREND: Stable
What is the grizzly bear?
The grizzly bear is a North American subspecies of the brown bear. Grizzlies are typically brown, though their fur can appear to be white-tipped, or grizzled, lending them their name. Grizzly bears are protected by law in the continental United States—not in Alaska—though there have been some controversial attempts to remove those protections in recent years.
