Comment by mncharity

> map!

Maps.[1][2]

Too far south for an ice bridge - Newfoundland is south like modern Florida - tropical. And it's the Jurassic, hot with high sea levels, so even though its continental shelf extends out towards Spain, there are no ice ages to bare it (as was the Eastern US shelf a mere 12k years ago). But Pangea is ripping apart, it's a mess with crust blocks variously uplifted and tilted, massive weathering and sediment fluxes, so...

From the TFA paper[3]:

During the early Mesozoic, North America and Europe were connected to form the western and central part of the supercontinent Laurasia. With the opening of the North Atlantic during the Late Jurassic and earliest Cretaceous, the region fragmented into smaller tectonic units55–58 that might have periodically formed contiguous land masses57,58 during sea level low-stands, characterized by exposure of continental margins and draining of continental interior seaways55–58. The presence of a land bridge between North America and Europe during the late Kimmeridgian-earliest Tithonian13 might explain similarities in some dinosaurs such as Stegosaurus59 and Allosaurus60. However, the absence of turiasaurs in the Morrison Formation suggests that this clade dispersed into western North America after the mid-Tithonian. Thus, unless we wish to argue that turiasaurs were actually present in the Morrison Formation but have not been found yet, a second later land connection between Europe and North America is required. Specifically, during the mid-Valanginian (c.137Ma), a dramatic drop in sea level7,55,56 potentially reconnected Europe and North America and so permitted a fi al exchange of vertebrate clades across the Atlantic. Th s Valanginian event could also explain apparent faunal exchanges between these continents proposed for the late Hauterivian-early Barremian13. Taxa that seem to disperse in the Hauterivian/ Barremian might actually have done so during the Valanginian lowstand, but gaps in the fossil record mean that the results of these dispersals might not be detected until we access better sampled post-Valanginian deposits.

58 is available with a plate.[4] 57 is old, with only low-res global plates, ggl books preview has 138 Ma on p42. 56 I skipped. 55 is available[5] but is temporally low res.

There's a 2016 paper Late Mesozoic North Atlantic land bridges[6], Elsevier paywalled with excerpts, and on sci-hub.

And that's my time budget.

[1] https://portal.gplates.org/cesium/?view=topo_recon [2] rocks: https://portal.gplates.org/cesium/?view=GeologyR key: https://portal.gplates.org/portal/geology/ [3] quote is on page 9: https://dinodata.de/bibliothek/pdf_d/2017/001_s41598-017-146... [4] paper ref 58, 150/136 Ma plates on page 31, key on page 29, 3 MB but downloads slowly: https://archimer.ifremer.fr/doc/00117/22805/20913.pdf [5] https://www.researchgate.net/profile/Golonka-Jan/publication... [6] Late Mesozoic North Atlantic land bridges (2016). Available on sci-hub. https://www.sciencedirect.com/science/article/abs/pii/S00128...