Thanks for your response to mine and Matt’s commentary. As for “hiding it”, it would be analogous to claiming that large sauropod dinosaurs had whip-like tails to lash out against hungry theropod dinosaurs. There is simply no proof from the fossil record that these dinosaurs had such an ability; with regards to teleost fish, I think yours could be best described as somewhat superfluous poetic license that might detract from your reporting of this very finding.

Thanks for your good points, and you’re right. I mischaracterized the impact of the study, so I’ve stricken the following sentence: “The finding complicates the study into the evolutionary transition of animals from water to land: the process didn’t necessarily include only transitional forms like the famous ‘fishapod’ Tiktaalik.”

John, re: “hiding it” — The point is only that this jumping ability, as noted, requires no noticeable anatomical peculiarity and thus hasn’t been left, or “recorded,” in the fossil record (as opposed to, for example, the mudskipper’s modified fins, which can be fossilized). Obviously the fish weren’t “trying to hide” this ability, or anything like that. It’s just a playful way of getting the point across in a headline.

You’re absolutely right that this study doesn’t “complicate our understanding of the evolutionary history of fish”, though to be more precise, we are referring only to bony fish (Osteichthyes), not to other “fishes” like sharks, rays and their relatives or hagfish and lampreys. But, with regards to the more derived Teleost clade of Osteichthyes, this study, based on experimental laboratory data, may support the hypothesis that this behavior could be indicative of a less derived trait that was common to the earliest Teleosts, not that it is “simply an extension of sinusoidal movement…. common among all fish.”

As for Douglas’ assertion that teleost fish have been “hiding it from the fossil record”, then that is quite a grand leap of faith. Why? Terrestrial environments are by their very nature, very poor environments for fossilization due to taphonomic aspects of the process of fossilization that have been demonstrated by such notable researchers of vertebrate taphonomy like physical anthropologist Pat Shipman and vertebrate paleobiologist Kay Behrensmeyer. In plain English, terrestrial environments are poorer than marine ones since they do not have locations that are easily subjected to rapid burial that would minimize decay of skeletal remains (via scavenging, microbial activity that would decompose such remains) and promote their potential preservation as fossils. Since terrestrial fossils are substantially rarer than those preserved in marine sedimentary strata, then one can’t say that terrestrial organisms, including some Teleosts, have been “hiding it from the fossil record”.

The study you’ve reported on merely documents, based on experimenta laboratory data, one probable evolutionary outcome in which one clade of Osteichthyes (bony fish) “invaded” a terrestrial environment sometime back in the middle Mesozoic Era (Jurassic Period, approximately 150 million years ago). The other example, well documented by the sequence that includes Tiktaalik, Acanthostega and Ichthyostega (long regarded as the “missing link” between lobe-finned bony fishes and tetrapods until recent discoveries by Clack, Shubin and others), dates from the middle to late Devonian Period of the Paleozoic Era (approximately 370 to 345 million years ago). For these reasons as well as those I mentioned yesterday, you can not conclude that “The finding complicates the study into the evolutionary transition of animals from water to land: the process didn’t necessarily include only transitional forms like the famous ‘fishapod’ Tiktaalik.”

No, I believe you should alter that comment lest someone thinks we don’t know the fish to tetrapod ancestor – descendant sequence which vertebrate paleobiologists Neil Shubin and Jennifer Clack, among others, have worked out in considerable detail in the past decade and a half (Shubin and his team discovered Tiktaalik; Clack’s team, Acanthostega.).

I’m not a student of paleoichthyology (I have a background in invertebrate paleobiology.), but unless I am mistaken, teleost fish arose in freshwater environments sometime during the middle Mesozoic Era (would be approximately the Jurassic Period if the 150 million year date is correct), so fish jumping could have been a less derived (“primitive”) trait that early teleosts used to avoid predation or to escape from pools of evaporating water, like some that are dry and wet depending on the seasons in question. As for it being a “complicating factor”, I would strongly doubt that, given our now extensive knowledge of teleost fish evolution from both paleobiological and genomic data.