Notochord, a flexible supporting rod along the back of an animal. It is present in all chordate animals at some stage in their development. A primitive chordate retains it throughout life. In higher vertebrate animals, the notochord is replaced before birth by a backbone.
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One of the great joys of traveling is sharing your new discoveries with your loved ones -- including your pets. Taking an animal abroad can be complicated, but there are plenty of good reasons to do it.
Have you ever brought your pet along for a visit with friends, only to have it turn into a disaster? Take this quiz for some dos and don'ts that will help ensure a pleasant visit for pets and humans alike.