Belemnites waxay ahaayeen xayawaan u eg dabacasaha oo ka tirsan fasalka cephalopod ee phylum mollusc. Tani waxay ka dhigan tahay inay la xidhiidhaan amooniyiinta qadiimiga ah iyo sidoo kale squid casriga ah, octopuses, cuttlefish iyo nautiluses. Waxay noolaayeen xilligii Jurassic (wuxuu bilaabmay c. 201 milyan sano ka hor) iyo xilligii Cretaceous (wuxuu dhammaaday 66 milyan sano ka hor). in dinosaurs la tirtiray. Wax badan ayaan ka naqaannaa sababtoo ah inta badan waxaa loo helaa sida fossils. Marka laga soo tago xogta sayniseed ee fossils belemnite, muddo ka dib waxaa soo baxay dhowr khuraafaad ah oo ku hareeraysan, maantana waxay sii ahaanayaan rikoodh soo jiidasho leh oo taariikhda hore ee dhulka. Belemnites waxay ahaayeen xayawaan badeed leh jidh dabagaalle oo kale ah oo maqaar leh, teendhooyin hore u fiiqan iyo siphon biyaha hore u sii saaraya, taas oo markaa dib ugu dhaqaaqday sababtoo ah kicinta jetka. Si kastaba ha ahaatee, si ka duwan squid casriga ah, waxay lahaayeen qalfoof gudaha ah oo adag.

Dib u dhiska belemnite caadiga ah

Sawirka Credit: Dmitry Bogdanov, CC BY-SA 3.0, via Wikimedia Commons

Dabada belemnite, qalfoofku wuxuu sameeyay qaab xabadu u eg oo mararka qaarkood loo yaqaan waardiye, ama ka badan.si sax ah, rostrum. Waa qaybahan adag kuwaas oo sida caadiga ah loo helo sida fossils, maadaama inta soo hartay unugyada jilicsan ee xayawaanka ay si dabiici ah u qudhuntay dhimashada ka dib.

Immisa jir ayaa jira fossils belemnite? laga soo bilaabo xilligii Jurassic labadaba (c. 201 - 145 milyan sano ka hor) iyo xilliga Cretaceous (c. 145.5 - 66 milyan sano ka hor), oo leh noocyo yar oo sidoo kale laga helay dhagaxyada taariikhiga ah ee Tertiary-dated (66 - 2.6 milyan sano ka hor) . Ilaalada belemnite waa qaab xabbadeed, sababtoo ah waxay ka kooban tahay calcite oo lagu dhejiyay meel. Runtii, fossils-ka waxaa loogu yeeraa 'dhagaxaan rasaas ah' waagii hore.

Waxaa cajiib ah, tusaaleyaal ka mid ah dhagxaanta Jurassic ee koonfurta England iyo koonfurta Jarmalka ayaa laga helay qaybo jilicsan oo weli jira. Sannadkii 2009, cilmi-nafsiga cilmi-nafsiga Dr Phil Wilby wuxuu ka helay kiishad khad belemnite ah oo la ilaaliyo oo ku taal Wiltshire, England. Kiishka khad madow, ee adkaaday, ayaa lagu qasay ammonia si rinji loo sameeyo. Rinjiga ayaa markaas loo isticmaalay in lagu sawiro xayawaanka.

Girigii hore waxay moodayeen in samada laga soo tuuray. 'belemnon', oo macneheedu yahay dart ama javelin. Giriiggii hore, fossils ayaa si weyn loo aaminsanaa in loo soo tuuray sida dart ama onkod samada ka yimid xilli roobaadka. Qaarkood waxay leeyihiin qaab far u eg, sidaas darteed suugaanta ayaa sidoo kale lagu naanaysi jiray 'Ibliis'Faraha 'iyo' St. Faraha Peter'.

Shark Hybodus oo leh waardiyayaasha belemnite ee caloosheeda, Matxafka Gobolka ee Taariikhda Dabiiciga ah Stuttgart

Sidoo kale eeg: Sida Knights Templar Aakhirkii Loo Burburay

Sawirka Sawirka: Ghedoghedo, CC BY-SA 3.0, iyada oo loo marayo Wikimedia Commons

Sidoo kale eeg: 8 Xaqiiqo ah oo ku saabsan Skara Brae

Sida fossils badan, belemnites ayaa la sheegay in ay leeyihiin awoodo daawo. Gobollada kala duwan waxay leeyihiin caadooyin kala duwan; si kastaba ha ahaatee, waxaa loo isticmaali jiray in lagu daweeyo laabotooyinka, indho-xanuunka iyo dhagxaanta mindhicirka ee fardaha.