fern and footprint 3d model

A kid-friendly shallow bas-relief plaque for 3D printing, in a thin rectangular slab with a flat back and rounded corners, designed for paper rubbings on a table. Include a realistic fern fossil on the left and a realistic three-toed dinosaur footprint fossil on the right, both as clean low-relief impressions with crisp edges and shallow depth. Keep the slab very thin to save filament, with a stable backing thickness of about 3 to 5 mm and a total relief depth of about 1 to 2 mm. Make the surface smooth, printable, durable, and easy to rub with crayons or pencils. No undercuts, no fragile spikes, no extra decoration, no text.