Aug 7, 2025
tardigrades, mud dragons and some other things
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tardigrades, mud dragons and some other things
Taxonomy Tournament: Ecdytes
Kinorhyncha. This phylum is made up of tiny benthic organisms, known as mud dragons
Priapulida. This phylum is made up of unsegmented marine worms known as penis worms.
Which clade of animals is better?
Kinorhyncha
Priapulida
Show results
Cambrian Explosion #35: Phylum Kinorhyncha
After the slightly unfortunately-shaped priapulids, let's move on to something much safer-for-work: dragons!
More accurately, kinorhynchs, tiny spiky scalidophoran worms with the delightful common name of "mud dragons". These animals weren't even discovered until the mid-1800s and are so small – less than 1mm (0.04") in size – that they're considered to be "meiofauna", wriggling around between grains of sediment using the spines on their heads to pull themselves along.
They're a widespread and abundant phylum with around 300 known living species, but they're also a very understudied group. Only a handful of scientists specialize in them worldwide and most research on them has been done in just the last 60 years, and so there are thought to be many many more species still out there to be discovered.
While these little dragons must have diverged from other scalidophorans at least as far back as the early Cambrian, they have basically no fossil record at all. A ghost lineage of over half a billion years.
Currently the only known exceptions to this are a few incredibly rare fossils from the early Cambrian of China. The recently-discovered Qingjiang fossil deposits (~518 million years ago) include some currently-undescribed specimens up to 4cm long (~1.5"), and if these do turn out to be kinorhynchs they indicate that modern forms may be highly miniaturized versions of much larger ancestors.
And some slightly older fossils from Sichuan, dating to about 535 million years ago, give us another possible ancient mud dragon: Eokinorhynchus rarus.
This species was much smaller than the Qingjiang forms but still twice as big as modern kinorhynchs at around 2mm long (0.8"). It had more body segments than living mud dragons, and a different pattern of spiny armor, suggesting it was probably part of an early stem-kinorhynch lineage rather than a true member of the group.
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King of The Mud Dragons
Mud dragons are just one type of meiofauna, animals so diminutive they live between grains of sediment. They swim through the watery film surrounding each grain, or navigate the terrain of sand and mud—veritable mountains to scale—using suction pads, hooks, or tiny toes. Just a handful of marine sediment is a meiofauna metropolis. They’re so numerous that under a single footprint on moist sand there could be up to 100,000 individuals. A brief walk, say just 85 steps, might tromp over eight and a half million organisms, a number equivalent to the population of New York City.
Kinorhynchs (aka mud dragons) range in size from about 0.13 to one millimeter. Like other meiofauna species, they are integral parts of marine food chains in sediments throughout the world. (Photo by María Herranz)
Taxonomy Tournament: Ecdytes
Loricifera. This phylum is made up of microscopic animals that attach themselves to gravel. It is one of the most recently discovered groups, first described in the 1980s
Kinorhyncha. This phylum is made up of tiny benthic organisms, known as mud dragons
Which clade of animals is better?
Loricifera
Kinorhyncha
Show results
today's invertebrate.......echinoderes drogoni
echinoderes drogoni works for minimum wage at a factory here they make slop, sludge and many other goopy products
so next time you use some sort of goop, blob, sludge, slop, bog, swamp, mucus or slime always thank echinoderes drogoni and the many other factory workers for their hard work, spending days just to get that goop to you
(pics by sanya-copepoda)
Echinoderes drogoni from Шпицберген on September 26, 2005 at 01:13 AM by Aleksandr Novikov. on sponges, depth 203 m