A crystalline glacial-wyvern with scales of translucent glacier ice and frosted silver horns, resting atop a massive polar ice shelf at astronomical twilight where aurora borealis ribbons dance across the frozen sky, scientific field notes cross-section mapping ice-crystal wing membrane thermal layers and cold-adapted glowing eye structures, palette of deep arctic indigo, glacial ice blue, aurora green and pale starlight silver, Victorian natural history polar expedition illustration aesthetic