Historical Papers
Baur, G. (1891). On the Relations of Carettochelys, Ramsay. American Naturalist. 1891:631-639.
Comment: The next of G. Baur's papers on the placement of Carettochelys within the Chelonia. The genius of Baur was his ability to correctly identify characteristics, that still hold up, with very little data. Not very scientific but certainly impressive. Scott Thomson (2004).
In may, 1886, prof. E.P. Ramsay, (1) of the Australian Museum, Sydney, described a peculiar new tortoise under the name of Carrotechelys insculptus¹. The description was based on an adult female (carapace, eighteen inches in a straight line), which was obtained in the Fly River, New Guinea. The new genus was referred to the Trionychidæ, forming "a link between the river tortoise and the see turtles." In 1887 Mr. Biulenger (2) placed this genus is a special family (Carettochelydidæ) of the Pleurodira, for the reason that the specimen was found in New Guinea, from which island only the PLeurodira are known. The charachters of this family were given as ; "Plastoral bones, nine. No epidermic scutes on the shell. Limbs paddle-shaped, with only two claws."
Prof. Gill, (3) nearly at the same time, wrote a review of Prof. Ramsay's paper, in which he reached a conclusion that the form is a type of peculiar family, Carettochelidæ, and that "it may quite likely prove to be a Pleurodire." Prof. Gill makes the following remarks : "But whatever the relations of the new genus, whether to the cryptodirous or pleurodirous tortoises, it has many quite peculiar charachters. From all known forms it is apparently disinguished by the absence of scuta, the perculiar feet, and other charachters. Undoubtedly, therefore, the new genus does not belong to any of the established modern families, and apparently not to any of the extinct ones named, although when more is known of Carettechleys, as well as the extinct forms, it may turn out that the Papuan animal is related to one of the families now regarded as extinct."
The family Carettechelydidæ of the Pleurodira was accpted by Mr. Lydekker (4) in the same year, and Hemicheyles Lydekker, from the lower Eocene of India, referred to it. In this form we have five neuralia in contact with each other, and there was probably a small mesoplastron present, according to Lydekker. To conclude from the figure, it seems that there were eleven peripherals on each side, as in the Pleurodira, for instance. I believe, therefore, that it is more likely a Pleurodiran than a near relative of Carettochelys.
In 1890 I published a short note on Carettochelys, (5) in which I doubted the Pleurodiran nature of the genus. I said ; "it is true it belongs the Pauarian regieon, in which, so far, only Pleurodira have been found. There ate some charachters, however, not seen in the Pleurodira, but in another group of Chelonians consisting of the families Cinosternidæ, Staurotypidæ, and Pseudotrionychidæ. It is only in this small group that we find wenty-one peripheralia (marginal bones), as in Carettochelys; the nueral bones are also reduced, and the latter charachter, however, I attach little value, as it may occur in any family.
"It seems to me that the systematic position of Carettochelys is far from being clear. How easily could the whole question be settled ! Mr. Ramsay would do a great service to science if he would undertaketo have the cervicals and the skull extracted, or the cervicals alone, If he fears for the skull. This could be done without injuring the specimen, and the structures of these parts would show at once the affinities of this peculiar genus."
Not doubting that Carettochelys would prove a very important form of the Testudinata, I rote to Prof. Ramsay, asking him if he could not examine the osteology of the animal, and publish a note about it. A short time before I recieved an answer I read Dr. Alexander Strauch's Bemerkungen ber die Schilddröten-sammlung im zoologshen Museum der kaeserlichen Akamemie der Wissenschaften zu St. Petersburg. (6)
Dr. Strauch, whose classification of the tortoises is far behind the times, and certainly not accepted by anybody---(he does not distinguish the Pleurodira from the Cryptodira, but places them in one group, Testudinida, of the same rank as the cheloniida! The unfortunate seperation of Dermochelys as a suborder Atheca is still kept up!)----places Carettochelys in a special "Abtheilung" of the Thecophora, with the name Carettechelda. "Ruckenschild herzformig mit Ranknochen. Brustchildknochen zu einer Platte verwachsen. Schale ohne Hornplatten Floasnfusse mit 2 Krallen. Phalangen der Zehen mit Condylen." Strauch remarks : "Sowit sich nach der allerdings noch shr unvollkommenen Beshriebung Ramsay's urtheilen lasst, muss seine Carettochelys inscupta unbeding zum Typus einer besondered, den Trionychiden und den Meershcildkroten gleich erthingen Famikie (nach Boulenger also Superfamilie) erhoben und im System zwichen diese beiden gestllt werden." Shortly after I had read Dr. Strauch's paper I recieved an answer from Prof. Ramsay, which I will give in full : "I recieved your note on Carettochelys in due time, but owing to the internal alterations going on in the museum the specimen could not be got at, and it is only now that I have been able to examine it. Alas ! there were no cervical vertebrae to examine ; the animal had served the explorer for food, and the whole of the bones, except the skull, had been cut away. I had this photographed for you, and hope it will help to place the very interesting from in its proper place. I shall be glad to help you in any way ; but there is nothing to work on, more than I have given in Proc. Linn. Soc. N. S. W., Vol. I., 1886, P. 158, with plates."