Happy Pride Month

Delphinus cruciger - Cross-Bearing Dolphin

“Another time, while crossing the vast space which exists between New Holland and Cape Horn, we observed in January 1820, at 49° latitude, other dolphins which had two broad white lines running nearly the entire length of their bodies on each side, intersected at right angles by a black line, which, when viewed from above, formed a black cross on a white background. They had a fairly sharp dorsal fin. We were not fortunate enough to capture them either. The same was true for the following species, which we met a few days later, distinguished by a white stripe on each side of the head. Perhaps it was a variety of the preceding species; perhaps this characteristic was only due to the fact that this individual was a juvenile: however, to distinguish them, we named the first cruciger [Delphinus cruciger] (plate 11, figures 3 and 4), the second albigene [Delphinus albigena] (same plate, figure 2).”

- Quoy and Gaimard, Voyage Autour du Monde, pp. 86-87

The plate mentioned above

As far as paper whales go, this is a borderline case, as this dolphin represents a known species. However, its markings are so distinctive in old illustrations that I wanted to feature it anyway.

Delphinus cruciger was a dolphin species documented in Antarctic waters in 1820 by Quoy and Gaimard, the same two naturalists who discovered the more famous Rhinoceros Dolphin. Its Latin name is best translated as “Cross-Bearing Dolphin” or, more directly, “Crucifer Dolphin”. It was named this because, from a bird’s eye view, its markings appear like a Christian cross (✟). A size estimate is not given for this dolphin.

I’ll admit my first reaction after discovering art of this species on the BHL’s Flickr page was to assume they were drawings of Southern Right Whale Dolphins, but I soon realized “D. cruciger” had a dorsal fin, which is conspicuously absent in Right Whale Dolphins (fun fact, this is how they got their common name).

Tangent: Right Whales were extremely valuable to whalers in the past, who quickly learned to identify the whales thanks to their lack of dorsal fins. Whether a cetacean had a dorsal fin or not seems to always have been noted. To draw a finless cetacean with a fin would be a grievous error, an error I’ve never seen made in any old illustrations of known finless species. Dorsal fins were always described well in old descriptions, I’m assuming because they’re one of the only features that are clearly visible above the water, and because of their value in species identification.

D. cruciger’s description is brief and also includes a description of a similar looking species, D. albigena, which the authors theorize may be the juvenile form of D. cruciger.

 

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It’s pretty widely accepted that Delphinus cruciger is a known species: the Hourglass Dolphin. The location and colors line up, and as the oldest known description of the species, the Hourglass Dolphin as we know it, Lagenorhynchus cruciger, still bares the same species name.

I’d like to use D. cruciger as a case study to illustrate the likely origin of many phantom dolphin species, which is the boring fact that dolphins are just straight up hard to identify from at-sea observations alone. You really have to capture and kill an individual in order to observe and describe it clearly. While it might seem unethical, physical specimens of animals or their skeletons/body parts need to be collected and preserved in order to establish a holotype, a preserved example of the new species being named. Every valid species named has one physical example living in a museum’s back room somewhere. Many “paper whales” are named despite lacking a holotype, a big reason why the species themselves are dubious. For cetaceans, holotypes are often skulls.

Here's the scene: You’re a naturalist aboard a corvette in the 1810s-1820s. You see a pod of dolphins playfully following alongside the ship, far below the deck. Failing to harpoon one, you draw what you think you saw briefly jumping out of the water to the best of your ability.

L'Uranie, the corvette Quoy and Gaimard would have been traveling on when observing dolphins in 1820

 

If you can only view the dolphins from the deck of a ship, the only parts of the body you can see clearly is the top half, leaving you to guess what markings might be on the belly. When you look at similar footage of Hourglass Dolphins bow-riding, you can start to understand why Quoy and Gaimard depicted the dolphin’s markings as belt-like rather than hourglass-like. It’s a reasonable depiction considering their limited view. I superimposed Q&G's D. cruciger illustration onto footage of actual Hourglass Dolphins so you can see what they were seeing.

Can you see it now?

 

Described alongside D. cruciger is D. albigena, which I believe this is also a shoddily-drawn Hourglass Dolphin. D. albigena will get its own entry on this blog, but I made a gif for it as well.

 

Cross-Bearing VS Hourglass

The Hourglass Dolphin retains the common name “Cross-bearing Dolphin” in the following languages:

•    Spanish (Delfín cruzado)
•    Portuguese (Golfinho-cruzado)
•    Italian (Il lagenorinco dalla croce)
•    Danish (Korshvidskæving)
•    Bulgarian (Кръстоносен делфин)
•    Russian (Крестовидный дельфин)
•    Serbian (Делфин крсташ)
•    Kazakh (Крест тәрізді дельфин)
•    Polish (Delfinowiec krzyżowy)
•    Vietnamese (Cá heo vằn chữ thập)

Interestingly, French seems to retain both variations of the common name, Dauphin sablier (Hourglass Dolphin) and Dauphin porte-croix (Cross-bearing Dolphin). I got these names from international Wikipedia articles. Other languages besides English that use the common name “Hourglass Dolphin” include German, Dutch, Swedish, Finnish, Turkish, Arabic, Persian, Korean and Indonesian.

A couple languages, like Catalan, Czech and Hungarian, use variations of “White-Striped Dolphin” or “Striped Dolphin”.

Bizarrely, in Hebrew, the dolphin is known as “Wilson’s Dolphin”, after a junior synonym, Lagenorhynchus wilsoni. Denis G. Lillie, who coined this name, was not the first person to describe the Hourglass Dolphin, but rather the seventh (Jefferson 2021). Another tangent: feel free to read Lillie's Wikipedia page, he seemed like an interesting character.

I’m really curious where the common name Hourglass Dolphin came from, since it certainly didn’t come from the Latin name.

The many faces of the Hourglass Dolphin

Delphinus cruciger and Delphinus albigena are not the only unique identities the Hourglass Dolphin has held. Another species, Delphinus bivittatus (Lesson and Garnot, 1827), is also very clearly another imperfect observation of the same species. D. bivittatus is notable for being described as very small, at 2 and a half feet long. Actual Hourglass Dolphins are more like 5-6ft long.

 

Delphinus bivittatus

The species was given yet another alias in 1893, Phocaena d’orbignyi (Philippi). However, the accompanying illustration is fairly accurate, and unmistakably an Hourglass Dolphin. The genus name Phocaena tells me that Philippi interpreted this species as a porpoise.

Phocaena d’orbignyi

 

The 1845 book Die vollständigste Naturgeschichte des In- und Auslandes features illustrations of all four variations.

All four variations depicted in Die vollständigste Naturgeschichte des In- und Auslandes

Illustration comparing these variations. I don't recall the source of this image.

If I may wax poetic....

I'm an atheist, myself. But there's a line from the bible I've always been fond of.

"For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known." 1 Corinthians 13:12

That particular line came back to me while working on this dolphin's artwork. Felt like a fitting note to end on for a crucifer.

 

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Shoutout to Lord Geekington for his blog post covering this same phantom species. His article is worth checking out in conjunction with this one, he made some of his own illustrative drawings as well.