So I've been doing some major updates to the Database for what will probably be a New Years upload, including the ornithuromorph section. One rather sad entry as it currently stands is the Antarctic Ichthyornis-
I? sp. (Zinsmeister, 1985)
Late Cretaceous
Seymour Island, Antarctica
Reference- Zinsmeister, 1985. 1985 Seymour Island expedition. Antarctic Journal of U.S. 20, 41-42.
Now with Googling I found the original paper online, which allowed only a bit of improvement-
I? sp. (Zinsmeister, 1985)
Late Maastrictian, Late Cretaceous
Lopez de Bertodano Formation, Seymour Island,
Antarctica
Material- several elements
Comments- Zinsmeister (1985) states "several small bones tentatively identified as belonging to the Cretaceous bird Ichthyornis were discovered in the upper Cretaceous Lopez de Bertodano formation."
Reference- Zinsmeister, 1985. 1985 Seymour Island expedition. Antarctic
Journal of U.S. 20, 41-42.
So I saw that Zinsmeister worked with Chatterjee in the 80s, who found the Polarornis holotype in the same place two years before that. I emailed Chatterjee about it, who replied-
"It was misidentified in the field. These were some shark teeth."
Mystery solved! But can we do better? Here's an Ichthyornis tooth-
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| Right eleventh dentary tooth of Ichthyornis dispar (YPM 1450) (after Field et al., 2018). |
And here's the array of shark teeth from the Lopez de Bertodano Formation of Seymour Island (from a January 2011 expedition). Can we find any easily confusable matches?
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| Chondrichthyan teeth from the Lopez de Bertodano Formation (scale 10 mm) (after Otero et al., 2014). |
I think the circled 16 and 17 are pretty decent matches for a field identification, though much larger if compared directly. Figures 6-17 are all identified as Odontaspidae indet., which covers any morphology similar to Ichthyornis. Add in the fact that they were by far the most abundant teeth recovered (8 samples versus 1-3 for the other taxa), and I think we have a nice solution on our hands.
I wonder how many other weird records are out there that are based on initial misidentification but stay in the literature because nobody ever publishes a correction?
References- Otero, Gutstein, Vargas, Rubilar-Rogers, Yury-Yañez, Bastías and Ramírez, 2014. New chondrichthyans from the Upper Cretaceous (Campanian-Maastrichtian) of Seymour and James Ross islands, Antarctica. Journal of Paleontology. 88(3), 411-420.
Field, Hanson, Burnham, Wilson, Super, Ehret, Ebersole and Bhullar, 2018. Complete Ichthyornis skull illuminates mosaic assembly of the avian head. Nature. 557, 96-100.
