spends more of its time in so-called 'REM' sleep than any other mammal.

These are the conclusions of a study on sleep in the platypus by Jerry M.

Siegel of the Sepulveda Veterans' Affairs Medical Center, North Hills,

California and colleagues. Their report appears in a special number of

Philosophical Transactions of the Royal Society devoted to the biology of

the platypus (Ornithorhynchus anatinus), celebrating the bicentenary of the

discovery, in Australia, of this remarkable animal.

'REM' stands for 'rapid eye-movement' and is the kind of sleep in which the

brain can be more active than in it is while awake, the animal twitches, and the

eyelids flicker - hence the name. In humans, REM sleep is associated with

But does the platypus have an extraordinarily rich dream life? Possibly not,

say the researchers: "cats, opossums, armadillos and other mammals not

Philosophical Transactions of the Royal Society devoted to the biology of

it, or if it evolved more than once, is something that only more work on birds

from the platypus itself, the group - the monotremes - includes two species of

obscure and extremely primitive creature, distantly related to humans. The

Despite these differences, the REM sleep of the platypus and the echidna is

observed in birds and some reptiles: in which case, the echidna may have lost

Some common words found in the essay are:
Tachyglossus REM, Royal Society, Australasia Monotremes, rem sleep, , Hills California, birds reptiles, sleep platypus, animals rem sleep, study sleep platypus, outward signs, brainstem activity, study sleep, animals rem, ancient roots, Center North, Siegel Sepulveda, Transactions Royal, Philosophical Transactions, North Hills, activity carried forwards, pathways brainstem, specific neuronal, properly defined characteristic, brainstem activity carried,
Approximate Word count = 3788
Approximate Pages = 15 (250 words per page double spaced)