Amoniti v Ljubljani
Amoniti so izumrla skupina morskih mehkužcev. V današnjih dneh jih najdemo v različnih kamnih, kot fosili iz preteklosti, nekaj takih fosilov je v kamnu na fasadi nekdanje Ljudske posojilnice.
Stavbo Ljudske posojilnice na Miklošičevi 4 je leta 1907 zasnoval arhitekt Josip Vancaš. Tipično secesijsko pročelje stavbe zaznamujeta keramična obloga v slogu dunajskega arhitekta Otta Wagnerja, in plitvi balkoni, ki spominjajo na slog Maksa Fabianija. Posebej izstopajo kovane balkonske ograje, ter konzoli z dekliškima glavama, ki zaključujeta osrednji, bogato okrašeni del pročelja. Na strehi sta dve sedeči ženski figuri, bosi in razkritih ramen, opremljeni z mošnjičkom, panjem in ščitoma, na katerih sta upodobljeni čebela in mravlja, simbola varčnosti, marljivosti in denarnega bogastva.
Amoniti so izumrla skupina morskih živali, in sicer podrazred Ammonoidea v razredu Cephalopoda (glavonožci), deblo Mollusca (mehkužci). So odlični fosilni kazalniki in pogosto omogočijo povezati plast, v kateri so najdeni, s specifičnimi geološkimi časovnimi obdobji. Najbližji sorodnik amonitov najverjetneje ni sodobni (po videzu podobni) Nautilus, temveč podrazred Coleoidea (hobotnica, ligenj in sipa). Njihove fosilne lupine imajo navadno obliko planispiral, nekatere pa so tudi polžasto zavite ali niso spiralne. Po spiralni obliki so tudi dobili svoje ime, saj spominjajo na ovnove rogove.
Večina amonitov je bila majhna, nekateri pa so imeli premer do 2 metra. Bili so zelo pogost plen pleziozavrov in ihtiozavrov. Imeli so lupino, ki je bila pri večjih amonitih debela do 5 centimetrov. Imeli so od 20 do 1800 kratkih lovk, ki so bile luskinaste ali pa poraščene z zelo redkimi kocinami.
Večina Amonitov najdemo v apnencih, včasih pa jih lahko najdemo tudi v drugih kamnih.
Fosili so ostanki odmrlega organizma okamenelih rastlin in živali, ki so se ohranile v zemljini, sedimentu ali kamenini iz starejših geoloških obdobij. Po odmrtju se mora takšen organizem dovolj hitro znajti v primernem okolju, kjer je onemogočeno njegovo hitro razpadanje. Takšni pogoji so bili in so še danes v raznih močvirjih, blatu, mulju, pesku, vulkanskem pesku, vulkanskem pepelu, smoli, zemeljskem vosku, katranu in podobnem. Primerno okolje sproži dolgotrajen fizikalno-kemičen proces, v katerem se odmrli organizem spremeni v fosil. Takšen proces imenujemo fosilizacija. Fosilizacija lahko poteka na več načinov, ki pripeljejo do različnih oblik fosilov.
Na steni bivše Ljudske posojilnice lahko najdete nekaj Amonitov.
Za vpis zaklada, kot najdenega odgovorite na spodnja vprašanja in mi odgovore posredujete preko GC profila, vendar ni potrebno čakati na moj odgovor, da bi zaklad označili kot najden.
Vprašanja:
1. Poglej amonite, ali misliš, da so odtis amonitov ali ostanki amonitov, ki so bili ujeti v kamen, glede na to, da so v apnencu?
2. Oceni velikost največjega amonita in v katero stran je zavit.
Ammonites in Ljubljana
Ammonites are an extinct group of marine mollusk animals in the subclass Ammonoidea of the class Cephalopoda. In now a days they can be found in different stones like a fossils from a past, a few fossils like that are on the wals of former People's Loan Bank building.
The People's Loan Bank building, located at No. 4 Miklošičeva ulica street, was designed by the architect Josip Vancaš in 1907. The most remarkable features of its distinctly Art Nouveau fasade are ceramic tiling in the style of the Viennese architect Otto Wagner and shallow balconies reminiscent of the style of Max Fabiani. Particularly striking are wrought iron balcony railings and the two corbels with girls' heads at the top of the central part of the building's richly decorated fasade. The roof is topped by two sitting barefoot female figures with bare shoulders holding a pouch, a bee-hive and a couple of shields bearing the images of a bee and an ant, the symbols of frugality, diligence and financial wealth.
Ammonites are an extinct group of marine animals belonging to the cephalopod subclass Ammonoidea. They lives from the Devonian until Late Cretaceous (417 - 65 million years ago) all over the world. Today living near relatives are coleoids, squid, octopus, and cuttlefish. Their name came from their spiral shape somewhat resemble tightly-coiled rams horns like the egyptian godhood Ammon.
The soft body of the creature occupied the largest segments of the shell at the end of the coil. The smaller earlier segments were walled off and the animal could maintain its buoyancy by filling them with gas. The shifting achieve by repulsion power.
They are main index fossils, and it is often possible to link the rock layer in which they are found to specific geological time periods. About 30.000 - 40.000 species are assumed. Therefore the ammonites are very important for geology.
The most of the Ammonites are found in limestone, but sometime they can be found also in marmor and other stones.
Fossils are most commonly found within sedimentary rocks due to the favorable conditions of burial and limited alteration through time. Sedimentary rocks form on the Earth's surface as sediment accumulates in rivers, lakes and on the seafloor in particular. Among the common sedimentary rocks include: sandstone, composed predominantly of grains of eroded rock; limestone, composed predominantly of shell debris and planktonic skeletons; and shale, formed from hardened clay (originally deposited as mud).
On very rare occasions fossils can also be found within igneous rocks where molten rock escapes to the Earth's surface and envelops organisms in its path, such as a tree. In this example if the molten rock cools and hardens in less time than it takes to turn the tree to ash, then the hardened rock may form a solid mould around the tree. Over a short period of time the tree tissues decay leaving an empty chamber inside the rock, some examples even preserve the texture of the outer bark on the walls of the mould.
You can find a few Ammonites on the wall of former building of People's Loan Bank building.
Here are the questions necessary for logging this cache as found. Please send the reply through the contact form, but do not wait for my reply, log right away.
Question:
1. Take a look of an Ammonites. Do you think that they are just a projection of Ammonies or there are real Ammonies caught in stone, according that you know that they are in limestone?
2. Estimate the size of the largest ammonite. In which side it is turned.
