Prof Shelley Edwards and her colleagues have described a new species of Psammophylax and a new genus, named after Prof Bill Branch, Kladirostratus…
The Grootswartberge (greater black mountain in Afrikaans), is a mountain range that runs along the southern part of South Africa.
To the south of it is the continental shelf and to the north of it is the Karoo – the important semi-desert biome that has many endemic species.
The mountain’s birth was tumultuous, with magma-induced uplift, folding, and warping. The dramatic changes drove the engine of evolution in biological organisms in the region.
“Creepy crawlies”
Evolutionary biologist, Prof Shelley Edwards, is an expert at showing how different species have adapted and evolved, and what the driving forces are for speciation events.
She fondly calls her study organisms “creepy crawlies” – reptiles and spiders – as she seeks to understand how changes in the environment over geological time create the diversity we see today.
“Before investigating the past evolutionary history of groups, we need to know how many species we are working with… thus, the first step in evolutionary analyses is to determine the taxonomic status of the group,” Shelley tells the FBIP.
She has chosen to focus on reptiles and spiders as much work has been done on mammals and birds in South Africa.
Skaapsteker
As part of a broader project, her team investigated a group of African grass snakes, Psammophylax. The relatively small, brownish-yellow, banded snake is commonly referred to as the skaapsteker (“sheep-stabber”) for the erroneous belief that they commonly bite and kill sheep.
Using phylogenetic analyses, traditional morphology, and geometric morphometrics the research team compared the snake groupings using the three methods. A hitherto undescribed group from Tanzania was identified.
The new species was named Psammophylax kellyi – in honour of Christopher Kelly for his considerable contribution to the systematics of the snake family Lamprophiidae.
Psammophylax kellyi
Tribute to Bill Branch
The team also named a new genus of Psammophiid snakes, Kladirostratus – the name is derived from the combination of the Greek word (Klodos) meaning “branch,” and the Latin word “rostratus” meaning beaked.
In their paper, the team suggests that the group be called “Branch’s Beaked Snakes,” a tribute to a beloved South African herpetologist.
“The name honours Professor William R. Branch (1947–2018), Curator Emeritus of herpetology at Port Elizabeth Museum, in recognition of his many contributions to the herpetology of Africa, especially regarding snakes.
“We benefitted from his generosity as a mentor and he helped shape our careers, for which we are thankful,” the article published in the Journal of Zoological Systematics and Evolutionary Research said.
These taxonomic studies are the springboard to other investigations.
Credit: ZSSA
Fracking possibility
Once Shelley, a Zoology & Entomology at Rhodes University researcher, has a “taxonomic” grip on what she is dealing with, she can proceed to understand which factors drove the speciation in the group.
Speciation drivers could include factors ranging from climate change, and human-mediated environmental change, to geological change. Once those factors have been identified, predictions can be made as to how biodiversity may be affected by future changes.
The Grootswartberge and the surrounding regions are contested at the moment.
Shelley says that over the past seven years, discussions have raged about the possibility of fracking (mining) in the Karoo, which could potentially lead to the extinction of endemic fauna (animals).
“Without a firm understanding of what species are present in the region, we can’t know what the impact of such mining activities would be on the local fauna,” she explains.
To understand which species are present, Shelley and her team investigated the potential drivers of species formation – the mountain ranges in the area.
If they found that species are isolated due to the mountain ranges, they could determine the value that would be lost if mining were to go ahead.
Shelley adds that her team is not the only group concerned about the potential loss of biodiversity in the region due to mining prospects.
“Much of the work in the Karoo (has been) done by SANBI in the BioGaps project.”
Watch the space
Shelley was awarded the SANBI Foundational Biodiversity Information Programme (FBIP) Small Grant in 2016 and managed to accomplish significant human capacity development during the project.
“Dr Chad Keates began his Masters investigating the grass snakes’ taxonomy and he upgraded to PhD and graduated with a doctorate in Herpetology in 2020.
“Our third-year and Honours Zoology students undertake research projects as part of their degree course, and around five students investigated various aspects of the project, resulting in good datasets that will be amalgamated into larger publications very soon!”
Shelley says the project is a work in progress as they are still discovering new spider species. Watch the space.
Have you ever had an experience with a skaapsteker snake? Let us know at d.mcdonald@sanbi.org.za