TheScientificEvolutionofanAlienArthropod(TheNorthernSonoma-canopy
CactusCrab)
AdaptationsIdentified
ThemutationoftheNorthernSonoma-canopyCactusCrabcameaboutdueto
climatechangeoveraperiodoftimedatingbacktotheMioceneepoch.The
upliftoftheSierraMadreOccidentalchangedtheweatherpatterns.All
tropicaldeciduousforestsandthornscrubturnedintoariddesertandthe
SonomaCrabhadtoevolveorbecomeextinct.Thispaperwillidentifythe
reasonsforitsadaptationsandincludethefollowing.
1. Modifiedjointedappendages(legsandfeet)
TheNorthernSonoma-canopyCactusCrabcantoleratetempeaturesof
60Corhigherforshortperiods.Longlegsallowthemtomoverapidly
andelevatetheirbodiesabovethescorchedsandandsalt-panterrainas
theyforagefordeadinsects.
2. Increasedsizeofjawandteeth
Theygettheirwaterfromtheirprey;theyhaveadaptedlargejawsand
increasedteethtofeedonthelargerdesertinsectsandtherefore
maximisetheirintakeofwaterwitheachfeed.
3. Additionalclaws
TheNorthernSonoma-canopyCactusCrabcansurviveinthedesert
becauseofitsabilitytoexcavateburrowsasmuchasametredeep
undertherootsoftheOpuntiamacrorhiza(pricklypearcactus)andstay
thereforupto6months.Itisabletodigsodeepbecauseofthehuge
clawswhichactasspadesfordiggingandalsoweaponsforhuntingprey.
FoodinthedesertissparseandsometimestheSonoma-canopyCactus
Crabhastohuntforfoodthatisbiggerthanitself.
4. Longtongue
Thisisusedtoaidbodytemperaturecontrol,whentheSonoma-canopy
CactusCrabstartstooverheatithangsitstongueout,itevaporates
moistureandreducesbodytemperature.Itisablue-blackcolourwhich
helpsthetonguefromgettingsunburned.Itisalsousedincatchingprey.
Thetongueisattachedtothefrontofthemouthratherthanattheback
likehumans.WhenaSonoma-canopyCactusCrabcatchesaninsectit
throwsitsstickytongueoutofitsmouthandwrapsitaroundits
prey.Thetonguethensnapsbackandthrowsthefooddownitsthroat.
5. Canopytail
Thisismadefromastrongbutthinwaxskin-likematerial.Itstaysclosed
andfoldedformostofthetimebutwhenexternaltemperatures
increaseandtheNorthernSonoma-canopyCactusCrabiscaughtoutin
thesunduringahuntingexpeditionitopensupandprovideswelcome
shadeovermostofitsbody.Itisonlyusedonrareoccassionsbecauseit
makesthecrabconspicuousandmayattractunwantedattentionfrom
itsmainhuntertheGreaterRoadrunner(Geococcyx).