Seven Distinct African Crocodile Species, Not Just Three, Biologists Show

Excellent; been waiting for the paper detailing the split of Mecistops for some time! As is usual for the journal it has been published in, it will be paywalled for a year after print publication then made open-access.

But for anyone with access, here is the link:

Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation

And for those like me without access, here is the abstract:

Accurate species delimitation is a central assumption of biology that, in groups such as the Crocodylia, is often hindered by highly conserved morphology and frequent introgression. In Africa, crocodilian systematics has been hampered by complex regional biogeography and confounded taxonomic history. We used rigorous molecular and morphological species delimitation methods to test the hypothesis that the slender-snouted crocodile (Mecistops cataphractus) is composed of multiple species corresponding to the Congolian and Guinean biogeographic zones. Speciation probability was assessed by using 11 mitochondrial and nuclear genes, and cranial morphology for over 100 specimens, representing the full geographical extent of the species distribution. Molecular Bayesian and phylogenetic species delimitation showed unanimous support for two Mecistops species isolated to the Upper Guinean and Congo (including Lower Guinean) biomes that were supported by 13 cranial characters capable of unambiguously diagnosing each species. Fossil-calibrated phylogenetic reconstruction estimated that the species split ± 6.5–7.5 Ma, which is congruent with intraspecies divergence within the sympatric crocodile genus Osteolaemus and the formation of the Cameroon Volcanic Line. Our results underscore the necessity of comprehensive phylogeographic analyses within currently recognized taxa to detect cryptic species within the Crocodylia. We recommend that the community of crocodilian researchers reconsider the conceptualization of crocodilian species especially in the light of the conservation ramifications for this economically and ecologically important group.
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To quote the part of that article particularly relevant to ZooChatters:

Austin said the team's work is leading to helpful information for American zoos and aquariums by decoding the correct identification and taxonomy of African crocodiles housed in these facilities. Without the correct species identification, zookeepers could interbreed these hard-to-distinguish species, rendering them ineffective as founder animals for conservation purposes. And captive breeding efforts may be wasted when individuals of different species simply won't breed.

"We're doing the work to see which species they actually have," Austin said.
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Hopefully they will share this information when its available, and also test the crocodiles in Europe.
 
Two Slender-Snouted, 3 Dwarf, and 2 Niles I assume.

A big week for new species.
 
zooboy28 said:
To quote the part of that article particularly relevant to ZooChatters:



Hopefully they will share this information when its available, and also test the crocodiles in Europe.
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Is ( party ) already done. For example a Dwarf crocodile from Oliemeulen in the Netherlands was send to the Czech Republic to be paired with a specimen of it's own species.
 
The type specimen of Mecistops cataphractus came [supposedly] from 'Senegal', so this name will apply to the West African form. Does anyone with access to the full paper know if the 'Congo Slender-snouted Crocodile' has been designated a scientific name?
 
Looking at the supplementary data, which is accessible to all, the new taxon is currently just referred to as Mecistops sp.nov - no idea whether it is given an actual name within the paper itself.
 
TeaLovingDave said:
Looking at the supplementary data, which is accessible to all, the new taxon is currently just referred to as Mecistops sp.nov - no idea whether it is given an actual name within the paper itself.
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Can someone find the paper in PLOS or other medium with full publication?

I find it a bit curious the writers do not yet have named it species-wise. The evidence is formidable and there for all to see and read. Perhaps any morphological studies awaiting publication first?

In Europe the diversion within Osteolaemus has already been put into practice. Sadly, C. cataphractus (which name has now become somewhat superfluous and having been superseded by the new genetic data) has not received very much attention from within zoological circles in Europe. Undeservedly so, to my mind … as equally fascinating as Tomistoma and Gavialis!
 
In 1835, Edward Turner Bennett of the ZSL named Crocodilus leptorhynchus, based on a specimen of slender-snouted crocodile kept at London Zoo. The specimen was thought to have come from the island of Fernando Po [now Bioko], and Bennett wrote that it differed from C. cataphractus in various minor ways. If this specimen is still retained - maybe at the Natural History Museum? - it may prove to be of the Central African form of slender-snout: which would make Mecistops leptorhynchus the valid name for the 'new' species.
 
I look forward to learning what the makeup of the European population is :)
 
Gulo gulo said:
Central African Slender-Snouted is Mecistops cataphractus, while the West African awaits a new taxonomic species name[/url]
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I don't see how that can be, given that the type locality for cataphractus was in West Africa.
 
Did you not click on the link and read the article?

“The central African slender-snouted crocodiles are now known as M. cataphractus. The west African species is still awaiting a new taxonomic species name. Genetic tests indicate the two crocs have been separate for at least seven million years."
 
Gulo gulo said:
Did you not click on the link and read the article?

“The central African slender-snouted crocodiles are now known as M. cataphractus. The west African species is still awaiting a new taxonomic species name."
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Yes, I read the article.
The article makes the statement that you quote.
The article does not explain the fact that the type locality for Mecistops cataphractus is "Senegal" [see, for example, Fuchs, K., R. Mertens, and H. Wermuth. 1974. Zum Status vom Crocodylus cataphractus und Osteolaemus tetraspis. Stuttgarter Beiträge zur Naturkunde. Serie A (Biologie) 266.
Unless there is good evidence to overturn this, the scientific name cataphractus should apply to the West African species.
 
@MikeG, I agree that the type locality should define the scientific naming process; hence Mecistops cataphractus for the West African form and the Central African species with an M. species novum .. (must check back with all the former species locality descriptions within Central Africa …).


The European Osteolaemus have been the subject of a genetic study and the populations of Osteolaemus are slowly being exchanged / transferred on the basis of the new knowledge.

Interesting suggestion by @Gulo Gulo that N.American crocs (this of course relates to Mecistops cataphractus … I am already using that name for West African see as per above) are all West African. Can you elaborate this with more information / data on the US zoo populations of slender-snouteds?

In the meantime that new paper by Shirley et al .. on the captives in US zoos is to be eagerly awaited ...
 
I've pulled the info from the latest article I posted yesterday. If you're having a meltdown and such and need help? Contact mshirley@ufl.edu. Matt can further elaborate if he chooses to do so.

Kifaru, I copied the info from the article as a teaser.

“Our results show that for Mecistops only the west African species is present in the United States,” he says. This is what I went on. How many are there in United States Zoos? Not 100% sure if the numbers reflect just Zoos or the private sector as well. There are Mecistops in private hands and I am not sure if they were all part of the testing.

Here is a page on Facebook. New Mexico BioPark Society and their involvement with Shirley. San Diego Zoo Global is involved too. Read amongst the posts as their Sr. Herp. Keeper Matt E. has been involved with preparing captive West African Mecistops there for their trip to U.S. as new founders. There are a dozen posts or so. Read them and enjoy the pictures from their trip.
https://www.facebook.com/nmbps?ref=ts&fref=ts
 
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