WebDescribed in 1911 by Charles Doolittle Walcott as an annelid, and in 1979 by Harry B. Whittington and Simon Conway Morris as a chordate, it became the "One of the most famous early chordate fossils," [1] or "famously known as relative the earliest" chordates. [2] It is estimated to have lived during the latter period of the Cambrian explosion. WebApr 15, 2024 · When will I get my first period? Most people start their periods between the ages of 12 and 13. However, it’s normal to start your period a little earlier or later, too. …
From water to land - Understanding Evolution
WebPrecambrian Era. formation of the one-celled organism, age of blue-green algae (Cyanobacteria) Precambrian Era. formation of the multi-celled organisms, green algae, … Web1) Chordate pharyngeal slits appear to have functioned first as A) the digestive system's opening. B) suspension-feeding devices. C) components of the jaw. D) gill slits for respiration. E) portions of the inner ear. D 2) Which of the following statements would be least acceptable to most zoologists? monahan fish fry
Solved Directions: Write the division and period of the - Chegg
WebFeb 24, 2024 · Scientists once agreed that the earliest true tetrapods dated from about 385 to 380 million years ago. That has all changed with the recent discovery of tetrapod track marks in Poland that date to 397 million years ago, which would effectively dial back the evolutionary calendar by 12 million years. WebJan 26, 2024 · The first period usually means that ovulation has occurred. Ovulation means that pregnancy is possible. However, both periods and ovulation can be irregular during the first few years after... WebIn 1938, a South African fisherman pulled a strange catch from the waters of the Indian Ocean. The iridescent blue animal had oddly fleshy fins that looked something like limbs. Scientists had seen fish like it before — but only preserved as fossils in ancient rocks. The fish was a coelacanth (SEE-luh-kanth), a member of the clade Sarcopterygii (sar-KOP … ian thain sap