Wednesday, July 20, 2011

[Palaeontology • 2010] Bonnerichthys gladius • Giant Suspension-feeding Bony Fish from the lower Upper Cretaceous of the United States

In artist's reconstruction of the 70-million-year-old giant suspension-feeding bony fish Bonnerichthys as it cruises through the seaway.
Art by Robert Nicholls,

Large-bodied suspension feeders (planktivores), which include the most massive animals to have ever lived, are conspicuously absent from Mesozoic marine environments. The only clear representatives of this trophic guild in the Mesozoic have been an enigmatic and apparently short-lived Jurassic group of extinct pachycormid fishes. Here, we report several new examples of these giant bony fishes from Asia, Europe, and North America. These fossils provide the first detailed anatomical information on this poorly understood clade and extend its range from the lower Middle Jurassic to the end of the Cretaceous, showing that this group persisted for more than 100 million years. Modern large-bodied, planktivorous vertebrates diversified after the extinction of pachycormids at the Cretaceous-Paleogene boundary, which is consistent with an opportunistic refilling of vacated ecospace.

• Gigantic filter-feeding fishes lived during the Mesozoic Era.
• Filter feeding didn't first emerge in whales, as had been previously suspected, but instead began with the now-extinct fishes.
• After the filter-feeding fishes died out with the dinosaurs, whales and other cetaceans filled the ecological niche.

Bonnerichthys jawbones and forefin/Matt Friedman

Fig. 2 Bonnerichthys gladius gen. nov., a giant suspension-feeding bony fish from the Upper Cretaceous of the United States. (A) Neurocranium and parasphenoid in ventral view. (B) Gular plate in ventral view. (C) Cranial and pectoral skeleton, shown in right-lateral view. Bones that were reconstructed from other specimens are shown in gray. (D) Hypural plate in right-lateral view. Scale bar in (C) applies to (A) to (D). (A) to (C) show specimen KUVP 60692; (D) shows specimen FHSM (Sternberg Museum, Hays, Kansas) VP-17428. (E) Tentative reconstruction in ventral (top) and lateral (bottom) views, indicating life position of bones shown in (A) to (D). ant, antorbital; ar, articular; cle, cleithrum; dsp, dermosphenotic; ect, ectopterygoid; f.hym, hyomandibular facet of neurocranium; op, opercle; p.f, pectoral fin; qu, quadrate; sco, scapulocoracoid; and sop, subopercle.

Matt Friedman, Kenshu Shimada, Larry D. Martin, Michael J. Everhart, Jeff Liston, Anthony Maltese and Michael Triebold. 2010. "100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas". Science. 327 (5968): 990–993. doi:10.1126/science.1184743.

SUV-Sized Fish Were Earliest Filter-Feeders : Discovery News

Feb. 18, 2010 -- Above is an artist's reconstruction of the 70-million-year old giant suspension-feeding bony fish Bonnerichthys as it cruises through the seaway covering what is today Kansas.
Researchers had believed that these prehistoric bony fish only existed for a short period of time, but newly examined fossils reveal that this group actually persisted for more than 100 million years during the Mesozoic.
By reinterpreting old findings and analyzing new fossils, researchers found that the massive suspension feeders, which engulfed water with an open mouth and sieved food while water escaped through gill slits, lived from 170 to 65 million years ago.
During that time, they pioneered the unique (and highly effective) filter-feeding strategies that can still be seen in the largest marine vertebrates living today.

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