Limulidae

Limulidae is a family of arthropods that live in marine and brackish environments. They are the only surviving members of the order Xiphosura, and are commonly known as Horseshoe crabs or Limules. The four surviving species of horseshoe crab are:


 * Carcinoscorpius rotundicauda, the mangrove horseshoe crab, found in South and Southeast Asia
 * Limulus polyphemus, the Atlantic or American horseshoe crab, found along the Atlantic coast of the United States and the Southeast Gulf of Mexico
 * Tachypleus gigas, the Indo-Pacific, Indonesian, Indian or southern horseshoe crab, found in South and Southeast Asia
 * Tachypleus tridentatus, the Chinese, Japanese or tri-spine horseshoe crab, found in Southeast and East Asia

Many available images depicting horseshoe crabs are not identified down to the species. This is why OpenTaxa links to them from a single page. We consider the identification of these uncertain images to be a part of the project's efforts, and contributions are highly appreciated! If you do so, please add your classification rationale as a part of your edits.

Media
Assessment (April 2022): Commons files depicting Limulidae include full-body photos, detail photos, videos, orthogonal line drawings, simple and full environmental illustrations. A good variety of files exist across a wide range of free licenses, but the vast majority are only depictions of Limulus polyphemus. Comparatively, all other species are poorly represented. For example, Carcinoscorpius rotundicauda has no illustrations clearly categorized as belonging to its species.

Many available images are not identified down to the precise genus/species. Some of the old illustrations are inaccurate, but tagged as such. Of note are illustrations depicting specific anatomical features and a series of microslides with preserved tissue samples from Limulus polyphemus, prepared by the Yale Peabody Museum of Natural History.

There exist a series of freely licensed, 3D photoscanned models of Limules from the Digital Atlas of Ancient Life, which were scanned from collections of the Paleontological Research Institution, Ithaca, New York, and are hosted on Sketchfab. Though the DAAL's website uses "horseshoe crab" to refer to Xiphosurids and not strictly speaking Limulidae, and thus also includes some fossil species in the same page, all are linked below for convenience until we create pages for the extinct taxa. Though more accurate and higher poly than the OGA model discussed below, they are not rigged nor animated.

The 3D model from OGA is fully modelled and textured, even in the complex underside, and includes a rig and several animations. It was created for a game on a fantasy setting, and so is relatively low-poly; with diffuse and normal textures; and is inaccurate, but being a .blend file (suitable for use with Blender) with all keyframes, textures etc. present, it could be modified for the creation of an accurate model.

OGA also hosts our release of top-down 2D sprites for C. rotundicauda. The pack includes top-down depictions of C. rotundicauda in a high-res pixel art style, with bodyparts in separate layers, seaweed and barnacle overlays, and the source file.

OpenTaxa assets
We released a set of CC-BY-SA 4.0 sprites for top-down depictions of C. rotundicauda in a high-res pixel art style. These include bodyparts in separate layers, seaweed and barnacle overlays, and the source file.

3D Scans

 * Xiphosurida at the Digital Atlas of Ancient Life
 * Direct Sketchfab links for all models in the page above: L. polyphemus 1 * L. polyphemus 2 * Carcinoscorpius rotundicauda * Tachypleus tridentatus * Mesolimulus walchi * Paleolimulus signatus

OGA 3D model

 * Swamp Limule by CDMir and TinyWorlds