Search results
Results from the WOW.Com Content Network
Chronic lymphocytic leukemia (CLL) is a type of cancer that affects the blood and bone marrow. [8] [9] In CLL, the bone marrow makes too many lymphocytes, which are a type of white blood cell. [8] [9] In patients with CLL, B cell lymphocytes can begin to collect in their blood, spleen, lymph nodes, and bone marrow.
First blood-sucking insects (ceratopogonids), rudist bivalves, and cheilostome bryozoans. Archaeopteryx, a possible ancestor to the birds, appears in the fossil record, along with triconodontid and symmetrodont mammals. Diversity in stegosaurian and theropod dinosaurs. 131 Ma First pine trees. 140 Ma Orb-weaver spiders appear. 135 Ma
This is a large taxon of insects. Some estimates of the species numbers suggest well over 10,000 world-wide. [2] Males are easily recognized by their plumose antennae.Adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects.
Many birds of Australia, like wrens and robins, look like Northern Hemisphere birds but are not related. [109] Oilbirds like microbats and toothed whales developed sonar-like echolocation systems used for locating prey. [110] The brain structure, forebrain, of hummingbirds, songbirds, and parrots responsible for vocal learning (not by instinct ...
The Jurassic) was important in the development of birds, one of the insects' major predators. During the early Jurassic period, the supercontinent Pangaea broke up into the northern supercontinent Laurasia and the southern supercontinent Gondwana ; the Gulf of Mexico opened in the new rift between North America and what is now Mexico's Yucatan ...
Possible early ancestors of catarrhines include Aegyptopithecus and Saadanius. 35-20 Ma Proconsul. Catarrhini splits into 2 superfamilies, Old World monkeys (Cercopithecoidea) and apes . Human trichromatic color vision had its genetic origins in this period. Catarrhines lost the vomeronasal organ (or possibly reduced it to vestigial status).
For premium support please call: 800-290-4726 more ways to reach us
Figure 1:In mammals, the quadrate and articular bones are small and part of the middle ear; the lower jaw consists only of dentary bone.. While living mammal species can be identified by the presence of milk-producing mammary glands in the females, other features are required when classifying fossils, because mammary glands and other soft-tissue features are not visible in fossils.