Alligators & Crocodiles

ISBN: 9780517070123

¶¨¼Û: 123.00

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CI~???()(]OIMLIAN???.; ~??????~. ???.~ .???.???.???.???d~.-v p.l..??? :..]. n.p ~. ~l????????? I.???~e of tl???e
Of Giants and Dragons ..???~??????e e??????able croc.odilians u~ dose off the wi???~dpipe??? a??????d
thus Io open Ihe month under waver when they seize their
TI. ~.roc~clilian~ mt memlwrs ~1 .u order ~d repHh s prey. They have a partition sep~ ali~ the chest from the
.???m~.hnu ???d I1. :tilit~au>rs. tl. ~lmria]. m~d the true erm o- rest of the body cavity??? rather like the diaphragm of
di5.~. The :m I1 1;???~1 Mn-vi??????m sofl}le???ffyc:d ~reupof rulin~ mammals??? This partition can be moved by means of a
~cplllcs . he alchosam s Amm1~ Owiv exiinc! relalives??? lhe muscle??? so thai crocodiliaes can breathe mere ef]]eiently
bp~bl??? town are Ih( mi~hh dim~sams??? All descended frmn thal~ ether reptiles.
cCmnnm~ ;~ neestm s IIw theeodonts??? wl i ich tlomished durin~~ The crocodilian heart??? too??? is closer to that of a mammal
th~ e~u-I~ \"lvia~si( period. 225 million years a~~o. The fossil than to those of oth er reptiles. ~iving them a more effieien!
[???.q/)rd ~11o ~ ??? I}IM ii}l)derll croeodi]iauts have ehan~ed very circulatory syslem. In most reptiles the heart has three
]lille sim ~ Iht!~ lirsl appeared??? about 160 million years a~e. chambers. Oxygenated blood from the hmgs and oxygen-
III |lit nid~q el an mlcxplained increase in lhe mlmbers of exhausted blood fi om the muscles and internal organs
]mu~ n.plih s. Vl.???n that stlr~Ce died down about sixty-five arrives in separate auricles??? but is then mixed in a common
millit.~ w.m-s a~.o. al the end of the Cretaceous period??? and ventricle??? The result is that some of the blood being pumped
II. rcsl ~t Ihe areho~ams disapl>eared - an equally unex- out into the ~eneral circulation is oxygen-deficient??? not
pl???su?????????~ ??????v~m! - urns| ot ~l~(~ croeodilians survived. Tl)ey are having passed throqg]??? the lungs to l)e recharged. In the
t1.??? ]ur~???~st livimz reptiles m the world??? fearsome and widely heart era croeodilian??? the ventricle is divided into two parts
fi~ared by a partition??? so that ~te-oxy~cenated blood goes only to the
COl.D-BLOODED IIORROR lungs and only fleshly oxygemtted blood passes into the
eireulation. ???
Th???.ve w sm.ethint\" aboul the combination of great size and These t~atures make erocodilians especially interesting to
cold blood thai i.spires horror in humans??? Elephants or biologists. As the only IMng relatives of the :treat dinosaurs???
~zovillas ~t???* hu\"e.ev Iml lhey are mammals like ourselves??? they provide a clue to the adaptations which may have made
inte]ti~. n! with d ]5mi]~ liD. Even lions and tigers are less the dinosaurs so successful tbr such a long period in the
;(~csoll~t- atlcl p~q stq ~lllOvl Ivy Kenerations of hunters??? all anilnal history of the earth.
l)m the sick ??????~ devau~ ed sh er well clear of mankind. We DRAGONS FROM FAR AWAY
t???v~???dil whale??? wilh tn ???*al intelliKenee??? and there are many
~1??????~ ~es ~d their ~clJ|]c belmvieur??? l~???ut crocodilians have no When the first explorers returned fl om Egypt to Greece and
I???.a~ m??????I ???.~~.ep??? it their parental be|mviour they are by no Rome??? they brought back stories of these powerful pre-
m~ am??? ~m~(le \"l he~ are pvedators??? of relatively limited daters??? Although their reports were t~ctual??? they mus~ have
mlclli~ n??? ??? cmd when they see a meal??? they take it??? I)een hard to believe??? anad legends inevitably grew up
wh~gh.-r it I???a~ Ibur h Ks m\" two. The dread in which they are around them. It cammt have been long betbre these stories
h(???hl I)~ mr)??????t oil].( hlllllall Yaet has hastened several Sl)ecies stirred recollections of ancient accounts of other great
???cr?????????ard??? px~mct???o?????? Fern has mtlt ushed many a spear??? and reptiles??? sprung not from travellers tales but fi om the
dl]~???.~ m~mv ~ .a]hq ~t~ its mark??? ilnaginalion t)J story-tellers??? or even fl Olll sollle distant
ANGIENTOR MODERN? tblk-u|emory of days when erocodilians still tlourished in
F??? urope and North America- and dragons were thus reborn.
Thr.??? .???.?????? h.~ ;tm .q.v. but cr*}??? odilians arc t]ol primitive in Long betbre the (h eeks and Romans??? the Egyptians had
???I???~ l??? ~m I hci~ bre;tlhiu~g al)par:flt~s is ].ighly de- first-hand knowledge el crocodiles??? fi em the cradle of their
. . i~(li/~d. The .???)strils m??? phte??? d al the very civilisation along the banks of the Nile. They regarded them
. th.d I1.. :twilnal can I;.t athc whcll Ihe i csl with awe??? and soon inehtded a crocodile??? Sebek??? among
d??????m J??????~ ???I ???~ xil???d aid h) ~.;um).fl;???~???c when il is their go(Is. Its eml>odiment on ear/h was a series (1~ sacred