Where Did the Bony Fishes Come From? – #UREES270 – 2018

Friedman and Brazeau, 2018, A reappraisal of the origin and basal radiation of the Osteichthyes: Journal of Vertebrate Paleontology, v. 30, p. 36-56 What’s it about? The authors look closely at the characteristics that distinguish osteichthians from other jawed fishes. They then review materials from fossil groups of fishes, in particular the Acathodii, and scoreContinue reading “Where Did the Bony Fishes Come From? – #UREES270 – 2018”

Pharyngeal Denticles and the Placoderms – #365papers – 2018 – 58

Johanson and Smith, 2005, Origin and evolution of gnathostome dentitions: a question of teeth and pharyngeal denticles in placoderms: Biological Reviews, v. 80, p. 303-345 What’s it about? This paper presents a detailed discussion of tooth development in fishes. In particular, the authors review the state of knowledge of tooth development in placoderms, among theContinue reading “Pharyngeal Denticles and the Placoderms – #365papers – 2018 – 58”

What if We’re Wrong About Placoderms? – #365papers – 2018 – 57

Zhu, Yu, Ahlberg, Choo, Lu, Qiao, Qu, Zhao, Jia, Blom, and Zhu, 2013, A Silurian placoderm with osteichthyan-like marginal jaw bones: Nature, v. 502, p. 188-193 What’s it about? I reported on another paper with Zhu as lead author sometime last week. That paper provided evidence that certain dermal bones (the dentary and maxilla), traditionallyContinue reading “What if We’re Wrong About Placoderms? – #365papers – 2018 – 57”

The Value of Fossils from the Margins of Basins – #365papers – 2018 – 53

Muldoon and Gunnell, 2012, Omomyid primates (Tarsiiformes) from the Early Middle Eocene at South Pass, Greater Green River Basin, Wyoming: Journal of Human Evolution, v. 43, p. 479-511 What’s it about? Much of this paper is a description of a new species of early primate, along with a description of the primate fauna from SouthContinue reading “The Value of Fossils from the Margins of Basins – #365papers – 2018 – 53”

How Do Teeth and Jaws in Placoderms Grow? – #365papers – 2018 – 52

Rucklin, Donoghue, Johanson, Trinajstic, Marone, and Stamponi, 2012, Development of teeth and jaws in the earliest jawed vertebrates: Nature, v. 491, p 748-752 What’s it about? Using tomographic data, the authors tease the different growth stages of the lower jaws of placoderms apart and show that the development of teeth are separate from the developmentContinue reading “How Do Teeth and Jaws in Placoderms Grow? – #365papers – 2018 – 52”

How Long Have Sharks Been Shark-y? – #UREES270 – 2018

Coates, Finarelli, Sansom, Andreev, Criswell, Tietjen, Rivers, and La Riviere, 2018, An early chondrichthyan and the evolutionary assembly of a shark body plan: Proceedings of the Royal Society B, v. 285, 20172418 What’s it about? This paper provides a new description of a 385-million-year-old fish called Gladbachus. This fish has characteristics of what we considerContinue reading “How Long Have Sharks Been Shark-y? – #UREES270 – 2018”

Whence Come the Teeth of Vertebrates? – #365papers – 2018 – 51

Smith, 2003, Vertebrate dentitions at the origin of jaws: when and how pattern evolved: Evolution & Development, v. 5, p. 394-413 What’s it about? Smith presents an argument that all teeth in vertebrates share a common origin, even though they look remarkably different, using evidence from growth lines in fossils, as well as developmental studiesContinue reading “Whence Come the Teeth of Vertebrates? – #365papers – 2018 – 51”

Where, Oh Where Do the Ganglia Go (in Lampreys) – #365papers – 2018 – 50

Modrell, Hockman, Uy, Buckley, Sauka-Spengler, Bronner, and Baker, 2014, A fate-map for cranial sensory ganglia in the sea lamprey: Developmental Biology, v. 385, p. 405-416 What’s it about? Fate-maps show where tissues in an embryo wind up in the adult. It is truly remarkable how cells move around in embryos. I mean, seriously. In thisContinue reading “Where, Oh Where Do the Ganglia Go (in Lampreys) – #365papers – 2018 – 50”

Wait? What Part of the Pharynx Becomes the Jaw? – #UREES270 – 2018

Cerny, Lwigale, Ericsson, Meulemans, Epperlein, and Bronner-Fraser, 2004, Developmental origins and evolution of jaws: new interpretation of “maxillary” and “mandibular”: Developmental Biology, v. 276, p. 225-236 What’s it about? Historically, it has been thought that the upper part of the first branchial (gill) arch becomes the upper jaw (maxillary) and the lower part of theContinue reading “Wait? What Part of the Pharynx Becomes the Jaw? – #UREES270 – 2018”

Placoderms, Dentary Bones, and the Origin of the Jaw – #UREES270 – 2018

Zhu, Ahlberg, Pan, Zhu, Qiao, Zhao, Jia, and Lu, 2016, A Silurian maxillate placoderm illuminates jaw evolution: Science, v. 354, p. 334-336. What’s it about? Placoderms are among the earliest vertebrates to have full-blown jaws. These jaws are develop from cartilagenous precursors that were once gill arches (or may have supported gills – that’s aContinue reading “Placoderms, Dentary Bones, and the Origin of the Jaw – #UREES270 – 2018”