BHL and Our Users: Joachim Ladwig

View Full Size ImageToday, we are excited to present Joachim Ladwig, a fossil collector in Germany with a passion for marine vertebrates. Though an amateur researcher, he has published a myriad of papers in amateur journals and holds among his repertoire of fossil finds the remains of a plesiosaur!

What is your title, institutional affiliation (or alternative place of employment), and area of interest?

I have no title or institutional affiliation! I work as a caretaker for a housing company in northern Germany and operate only as an amateur researcher.

I was born in 1962 and live in the federal state of Schleswig-Holstein. I’m a member of the “Gesellschaft für Geschiebekunde” (Society for Glacial Erratic Boulders), a cooperation of scientists (mainly from the Universities of Hamburg and Greifswald) and amateur collectors researching erratic boulders, which are the most important source of fossils in northern Germany.

How long have you been in your field of study?

I have been collecting fossils for more than 20 years. Soon after I began collecting, I undertook research (as an amateur) on fossil marine vertebrates, mainly from the Cretaceous period. One field of interest is sea-urchins, but I am especially interested in sharks and bony fish and their main fossil remains: teeth.

Some years ago I found the remains of a very great plesiosaur in a chalk-pit here in northern Germany. Since then I have been looking for literature on marine reptiles (mosasaurs and plesiosaurs), too.

When did you first discover BHL?

I think it was about 2 or 3 years ago, when I used Google to search for pdf-files of scientific papers on the internet.

What is your opinion of BHL and how has it impacted your research?

Because it was often very difficult to get old literature (and when you get it photocopied from your library the quality of the picture is miserable), it’s a great improvement to have access to pdf-files of these antique papers. To determine, for example, which species of fossil shark a find belongs to, it is necessary to take a look at the original descriptions. When you don’t have direct access to a university library, BHL is sometimes the only way to see these publications!

One concrete example: For 20 years I tried to find out which species the cow shark teeth in the northern German chalk belong to – Hexanchus microdon or Hexanchus gracilis. In BHL I found the original papers in which these species where described. Now I am very sure of the identification: My fossil cow shark teeth belong to Hexanchus microdon.

How often do you use BHL?

Several times a month.

How do you usually use BHL (read the titles online/download whole PDFs/Selecting Pages to Download for a custom PDF/Downloading High Resolution Images/Generating Taxonomic Bibliographies/etc.)

Generally, I download the whole pdf-file. I even print important papers. It’s not comfortable for me to read on the monitor; I prefer to read it on a piece of paper!

In the last years I have collected a whole hard-disk-drive of pdf files. They are not all from BHL, but many of the important and/or old ones are.

If you could change one thing about BHL, what would it be, or what developmental aspect would you like the BHL team to focus on next?

Very often I find that whole volumes of a journal are scanned as one file, but usually I only need one short paper. So I have to download an immense amount of data (806 pages!), while I cite only a small portion of it (for example, the work I cite in the next paragraph). It would be very useful to divide these big scans into smaller ones!

If you had to choose one title/item in BHL that has most impacted your research, or one item that you prefer above any other in BHL, what would it be and why?

I had looked for a long time for this paper:

“DAVIS, J.W. (1887): The fossil fishes of the Chalk of Mount Lebanon, in Syria. – The Scientific Transactions of the Royal Dublin Society, 3 (Series 2): 457 – 636, Taf. 14 – 38; Dublin”

I found it at BHL.

It contains the original description of Hexanchus gracilis, a species of cow shark, which is often found in the upper cretaceous layers in northern Europe. I was trying to find out if it is a valid species or not. The plates in this work are very beautiful. They are not only of scientific interest, but are an art, too. I’m very pleased that I can use a reproduction from one of these plates for a planned publication.


Thank you, Joachim, for your contribution to the scientific realm and your willingness to share some of it with us! We are aware that article-level access to our content is a critical development for BHL, as it is one of our most user-requested improvements. We are currently working on models that will allow this level of access, but for the time-being you can find many BHL articles in our article repository Citebank.

Be sure to check out a bibliography of some of Joachim Ladwig’s publications below. We’re thrilled to know that BHL is helping him, and many others, identify and learn more about the fossilized remains of the magnificent biodiversity that lived ages ago.

A list of Joachim Ladwig’s former publications in amateur journals:

  • CLAUßEN, M. & LADWIG, J. (1997): Das Kieferfragment eines Mosasauriers aus dem Obercampan von Kronsmoor. – Der Geschiebesammler, 30 (3): 127 – 130, 3 Abb.; Wankendorf.
  • LADWIG, J. (1993): Fund eines Zahnes von Hexanchus gracilis. – Der Geschiebesammler, 26 (4): 161 – 163, 2 Abb.; Wankendorf.
  • LADWIG, J. (1994): Haizähne aus Oberkreide- und Dan-Geschieben. – Der Geschiebesammler, 27 (3): 105 – 110, 4 Abb.; Wankendorf.
  • LADWIG, J. (1995): Haizähne aus dem Obercampan von Kronsmoor. – Der Geschiebesammler, 28 (4): 143 – 152, 9 Abb.; Wankendorf.
  • LADWIG, J. (1997): Mosasaurierreste aus Schleswig-Holstein. – Fossilien, 1997 (6): 358 – 362, 8 Abb., 1 Zeichn.; Korb.
  • LADWIG, J. (1998): Fischreste aus dem Echinodermenkonglomerat. – Der Geschiebesammler, 31 (4): 177 – 186, 3 Abb., 1 Taf.; Wankendorf.
  • LADWIG, J. (2000a): Haizähne aus dem Obercampan von Kronsmoor. Teil 2. – Der Geschiebesammler, 33 (2): 77 – 90, 3 Abb., 3 Taf.; Wankendorf.
  • LADWIG, J. (2000b): Fischzähne aus dem Obercampan von Kronsmoor. – Der Geschiebesammler, 33 (3): 125 – 130, 4 Abb.; Wankendorf.
  • LADWIG, J. (2002): Möglicher Neufund von Protoxynotus misburgiensis HERMAN 1975. – Arbeitskreis Paläontologie Hannover, 30 (2): 36 – 41, 1 Abb.; Hannover.
  • LADWIG, J. (2003): Erstnachweis eines Zahnes von Ptychodus latissimus AGASSIZ 1843 aus dem Geschiebe. – Der Geschiebesammler, 36 (2): 43 – 46, 1 Abb.; Wankendorf.
  • LADWIG, J. (2006a): Haizähne aus dem Turonium von Wüllen. – Arbeitskreis Paläontologie Hannover, 34 (1): 1 – 9, 12 Abb.; Hannover.
  • LADWIG, J. (2006b): Fundbericht: Haizahn Cretolamna appendiculata aus Misburg. – Arbeitskreis Paläontologie Hannover, 34 (1): 10 – 11, 1 Abb.; Hannover.
  • LADWIG, J. (2008): Reste des rätselhaften kreidezeitlichen Fisches Cylindracanthus cretaceus (DIXON, 1850) aus Kronsmoor (Schleswig-Holstein). – Arbeitskreis Paläontologie Hannover, 36 (1): 12 – 22, 7 Abb.; Hannover.
  • LADWIG, J. (2009): Anmerkungen zur Seeigel-Gattung Bolbaster aus dem Danium von Dänemark. – Der Geschiebesammler, 42 (4): 165 – 173, 2 Abb., 2 Taf.; Wankendorf.
  • LADWIG, J. (2011a): Erstnachweis des Haies Gladioserratus aptiensis (PICTET, 1865) (Neoselachii, Hexanchiformes) aus der nordwestdeutschen Oberkreide. – Arbeitskreis Paläontologie Hannover, 39 (3): 99 – 104, 3 Abb.; Hannover.
  • LADWIG, J. (2011b): Der seltene Seeigel Galeaster bertrandi SEUNES, 1889 aus einem Dan-Geschiebe von Norderbrarup. – Der Geschiebesammler, 44 (2): 47 – 51, 1 Abb., 1 Taf.; Wankendorf.
  • LADWIG, J. (2012): Eine Exkursion ins Maastrichtium und Danium der Insel Seeland, Dänemark. – Arbeitskreis Paläontologie Hannover, 40 (1): 3 – 12, 9 Abb.; Hannover.
  • TÜXEN, H. & LADWIG, J. (1998): Ein Mosasaurierzahn aus einem weißgefleckten Feuerstein. – Der Geschiebesammler, 31 (3): 137 – 141, 2 Abb.; Wankendorf.

Some publications available for free download:

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Grace Costantino served as the Outreach and Communication Manager for the Biodiversity Heritage Library from 2014 to 2021. In this capacity, she developed and managed BHL's communication strategy, oversaw social media initiatives, and engaged with the public to excite audiences about the wealth of biodiversity heritage available in BHL. Prior to her role as Outreach and Communication Manager, Grace served as the Digital Collections Librarian for Smithsonian Libraries and as the Program Manager for BHL.