
spheragnostus

ariyappedunna phoosil maraine aarthropodukalude oru vibhaagathil ninnulla trilobiteukalil ninnulla vamshanasham sambhavicha oru janussaanu sphairagnostus. poornnamaayum illaathaaya headshield (allengil sephalon) enna rund thorax segmentukal ullathiloode ithu thirichariyaan kazhiyum, athesamayam tailshield (allengil pigidium) illaathaayengilum athinte athirthikku samaantharamaayi vyakthamaaya romavum hraswavum convex, subsercular axis undu. ithu oordovishiyan kaalaghattatthilaanu (upper tremadoc muthal ashgil vare) jeevichirunnathu.
vargeekaranam.
spheragnostasine" mattu agnostidukalumaayi bandhappeduthunnathu budhimuttaanu, eee januss agnostoidia, contilopygoidia, allengil oru puthiya monotypic suuppar famili ennivaykku nalkano ennu theerumaanikkappettilla.
vivaranam.
ellah agnostida pole, "spheragnostus" cheruthum sephalone pyjidiyavum ekadesham ore valipavum rooparekhayum (allengil isopigius) ullathumaanu. ellah agnostinayeyum pole, sphairagnostasinum rund thorax segmentukal maathrameyulloo. sephalon baahyamaayi poornnamaayum illaathaakukayum athirthi romangal, aksheeya romangal, glabeller nooad enniva illaathathumaanu. thorax segmentukalude pleural pradeshangal valare cheruthaanu, athesamayam achuthandu valare veethiyullathum (madhyarekhaykku lambamaayi) shradheyamaayi hraswavumaanu (achuthandil). pigidiyathinu nannayi nirvachikkapetta athirthi romangalum idungiya athirthikalumundu. aksheeya romangal aksheeyavum anthimavumaaya nodukal vahikkunna hraswavum vishalavum convex, subsercular, unfroved axis ennivaye nirvachikkunnu. ithinu oru median postaaksiyal arra illa. pigidiyatthinte "pinn konukalil" nattellukal undengil, iva minittaan.
leagnostasumaayulla vyathyaasangal.
sphairagnostus" enna sephalonukal valare illaathaakukayum "leagnostus" inam poleyaakukayum cheiyunnu. ennirunnaalum, "spheragnostus" ennathinte pigidia, minusamaarnnathum ennaal eluppathil thirichariyaan kazhiyunnathumaaya upavrithaakruthiyilulla mattu vamshangalil ninnu vyathyasthamaan.