Teeth were an important innovation in vertebrate evolution but basic aspects of early dental evolution remain poorly understood. Teeth differ from other odontode organs, like scales, in their organised, sequential pattern of replacement. However, tooth replacement patterns also vary between the major groups of jawed vertebrates. Although, tooth replacement in stem- osteichthyans and extant species has been intensively studied it has been difficult to resolve scenarios for the evolution of osteichthyan tooth replacement because of a dearth of evidence from living and fossil sarcopterygian fishes. Here we provide new anatomical data informing patterns of tooth replacement in the Devonian sarcopterygian fishes Onychodus, Eusthenopteron and Tiktaalik and the living coelacanth Latimeria based on microfocus- and synchrotron radiation-based X-Ray microtomography. Early sarcopterygians generated replacement teeth on the jaw surface in a pattern similar to stem-osteichthyans, with damaged teeth resorbed and replacement teeth developed on the surface of the bone. However, resorption grades and development of replacement teeth vary spatially and temporally within the jaw. Particularly in Onychodus, where teeth were also shed through anterior rotation and resorption of bone at the base of the parasymphyseal tooth whorl, with new teeth added posteriorly. As tooth whorls are also present in more stem-osteichthyans, and statodont tooth whorls are present among acanthodians (putative stem-chondrichthyans), rotational replacement of the anterior dentition may be a stem-osteichthyan character. Thus, our data are compatible with a disparate pattern of evolution of tooth replacement and more complex evolutionary history of jawed vertebrates.
MDXR01a_Onychodus_maxilla
Onychodus jandemarrai left maxilla (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR01d_Onychodus_maxilla_ROI_part1
Onychodus jandemarrai maxilla (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR01d_Onychodus_maxilla_ROI_part2
Onychodus jandemarrai maxilla (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR01d_Onychodus_maxilla_ROI_part3
Onychodus jandemarrai maxilla (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR02a_Onychodus_dentary_part1
Onychodus jandemarrai dentary (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR02a_Onychodus_dentary_part2
Onychodus jandemarrai dentary (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR02b_Onychodus_dentary_ROI
Onychodus jandemarrai dentary (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MDXR03_Onychodus_ectopterygoid
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
MR153a_Onychodus_ectopterygoid_synchrotron_part1
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part2
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part3
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part4
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part5
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part6
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part7
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MR153a_Onychodus_ectopterygoid_synchrotron_part8
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part1
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part2
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part3
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part4
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part5
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part6
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part7
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part8
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_2b_Onychodus_ectopterygoid_synchrotron_part9
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part1
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part2
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part3
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part4
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part5
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part6
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part7
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part8
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part9
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_6c_Onychodus_ectopterygoid_synchrotron_part10
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part1
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part2
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part3
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part4
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part5
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part6
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part7
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part8
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part9
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part10
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part11
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part12
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_10c_Onychodus_ectopterygoid_synchrotron_part13
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part1
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part2
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part3
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part4
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part5
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part6
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part7
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part8
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part9
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part10
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part11
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part12
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part13
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
MDXR03_16_Onychodus_ectopterygoid_synchrotron_part14
Onychodus jandemarrai ectopterygoid (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) SRXTM data
XMR3a_Onychodus_tooth_whorl
Onychodus jandemarrai parasymphyseal tooth whorl (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
XMR3b_Onychodus_tooth_whorl
Onychodus jandemarrai parasymphyseal tooth whorl (NHMUK PV P63570, Frasnian, Gogo Formation, Western Australia) micro-CT data
Efoordi1_Eusthenopteron_lower_jaw
Eusthenopteron foordi lower jaw (NRM-PAL P.35, Frasnian, Escuminac Formation, Miguasha National Park, Canada) micro-CT data
MDXR05a_Eusthenopteron_lower_jaw
Eusthenopteron foordi lower jaw (NRM-PAL P.35, Frasnian, Escuminac Formation, Miguasha National Park, Canada) micro-CT data
Tiktaalik_dentary_part1
Tiktaalik roseae lower jaw (NUFV666, Frasnian, Fram Formation, Nunavut territory, Canada) micro-CT data
Tiktaalik_dentary_part2
Tiktaalik roseae lower jaw (NUFV666, Frasnian, Fram Formation, Nunavut territory, Canada) micro-CT data
Tiktaalik_dentary_part3
Tiktaalik roseae lower jaw (NUFV666, Frasnian, Fram Formation, Nunavut territory, Canada) micro-CT data
Tiktaalik_dentary_part4
Tiktaalik roseae lower jaw (NUFV666, Frasnian, Fram Formation, Nunavut territory, Canada) micro-CT data
Tiktaalik_dentary_part5
Tiktaalik roseae lower jaw (NUFV666, Frasnian, Fram Formation, Nunavut territory, Canada) micro-CT data