Schinderhannes bartelsi

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Fans of the great Cambrian predator, Anomalocaris, will be pleased to hear that a cousin lived at least until the Devonian, over 100 million years later. That makes this a fairly successful clade of great-appendage arthropods — a group characterized by a pair of very large and often spiky manipulatory/feeding arms located in front of the mouth. Here’s the new fellow, Schinderhannes bartelsi:

schinderhannes.jpeg

(click for larger image)
Holotype of Schinderhannes bartelsi. (A) Ventral. (B) Interpretative drawing of ventral side. l, left; r, right; A1, great appendage; A2, flaplike appendage; sp, spine; fm, flap margin; te, tergite; ta, trunk appendage. (C) Partly exposed dorsal side, horizontally mirrored. (D) Interpretative drawing of dorsal side. (E) Interpretative drawing of great appendages, combining information from the dorsal and ventral sides. (F) Radiograph. (G) Reconstruction. Scale bar, 10 mm [for (A) to (G)]. (H) Mouth-part. Scale bar, 5 mm.

There are some significant differences between familiar old Anomalocaris and Schinderhannes. Anomalocaris was a monster that grew to about a meter long; this little guy is about a tenth of that, around 4 inches. He also has those interesting “wings” behind his head, which presumably aided in swimming.

Another significant feature of this animal is that it has characters that place it in the Euarthropoda, which makes great appendages paraphyletic and primitively present in euarthropods. Those great appendages have long been a curiousity, and we’ve wondered whether they are a unique innovation that was completely lost in modern arthropods, or whether they evolved into one of the other more familiar cephalic appendages; the authors suggest that this linkage with the euarthropod family tree implies that chelicera (what you may recognize as the big paired ‘fangs’ of spiders) are modified great appendages.

schinderhannes_clade.jpeg

Cladogram; tree length, 87. Consistency index, 0.5402; retention index, 0.6552. (1) Peytoia-like mouth sclerites, terminal mouth position, lateral lobes, loss of lobopod limbs, and stalked eyes. (2) Great appendages. (3) Sclerotized tergites, head shield, loss of lateral lobes, and biramous trunk appendages. (4) Stalked eyes in front and loss of radial mouth. (5) Post-antennal head appendages biramous and antenna in first head position. (6) Free cephalic carapace, carapace bivalved, and two pairs of antennae. (7) Maxilla I and II. (8) Exopods simple oval flap. (9) Two pre-oral appendages and a multisegmented trunk endopod. (10) Post-antennal head appendages biramous and tail appendages fringed with setae. (11) Long flagellae on great appendage and exopods fringed with filaments. (12) Trunk appendages uniramous and eyes not stalked. (13) No posterior tergites. (14) Tail spines and chelicere/chelifore on first head position. (15) Proboscis. (16) Six post-antennal head appendages.


Kühl G, Briggs DEG, Rust J (2009) A Great-Appendage Arthropod with a Radial Mouth from the Lower Devonian Hunsrück Slate, Germany. Science 323(5915):771-773.

4 Comments

Wonderful! Thanks for the heads up.

So cool that we begin to see a way that Anomalocaris is not such an anomaly, but actually related, and to the spiders. I’ve long loved this species, and was excited to see my first fossil of it in person at the UW Geology Museum.

Just shows you how much we may not know about early metazoan diversification. I think it’s absolutely incredible that an Anomalocaris relative survived the great late Ordovician mass extinction, and found a successful niche for itself nearly one hundred and thirty million years after its larger, more dangerous, relative.

The discovery of this Anomalocaris relative is analogous to finding a living pygmy Velociraptor in the Amazon jungle. This is why this discovery is so important.

It is really incredible that the Anomalocaris clade persisted long after the time it was thought to go extinct, after the end of the Middle Cambrian Burgess Shale Fauna. Why? Here you have the descendant of what was the keystone species - the top predator - of the Middle Cambrian seas - still existing as a specialized niche predator many millions of years later. A relatively “primitive” predator in stark contrast to the more “advanced” eurypterids (sea scorpions) and placoderms (earliest jawed vertebrates) which became the top predators during the succeeding Ordovician and Silurian periods.

Speaking of the Burgess Shale Fauna, one of this paper’s authors, DEG Briggs is the very Derek E. Briggs, who, along with his graduate advisor, Harry Whittington, and then fellow graduate student Simon Conway Morris, quite literally “re-wrote the book” on our understanding of the Burgess Shale Fauna, which, Stephen Jay Gould recounted - if a bit incorrectly - in his popular book “Wonderful Life”. Briggs is now a professor of geology and Director, Peabody Museum of Natural History, at Yale University.

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This page contains a single entry by PZ Myers published on February 10, 2009 6:08 PM.

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