Hollardops

Hollardops is a genus of trilobite in the order Phacopida that lived during the Devonian. Their fossils are found in the upper Emsian of western Europe and in the lower Emsian to lowermost Eifelian of North Africa. The type species, Asteropyge mesocristata, was described from Algeria by Le Maître in 1952. The genus Hollardops was erected by Morzadec in 1997. In the same year, Lieberman & Kloc erected Modellops and Philipsmithiana but those genera are regarded as subjective synonyms of Hollardops. The 10-segmented thoracic condition of Hollardops is a rare feature among acastid trilobites that almost always have 11 thorax segments. Van Viersen & Kloc (2022) revisited Hollardops and described a number of new species from the Devonian of Morocco. They also regarded Pennarbedops Bignon & Crônier, 2013 as a synonym of Hollardops. Van Viersen & Kloc construed Hollardops as a scavenger or predator with well-developed eyes, that used its shovel-like cephalon to plough the top layers of the sediment in search of food. Hollardops had small pits horizontally along the fringe of the exoskeleton; these are believed to have housed setae that allowed the trilobite to closely monitor its surroundings.

Hollardops

Daderot · CC0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.

On record

Recorded, not inferred
Sits inside
AcastidaePBDB
Diet
carnivorePBDB, for Phacopina
Life habit
low-level epifaunalPBDB, for Trilobita
Motility
fast-movingPBDB, for Trilobita
Vision
well-developedPBDB, for Acastidae
Environment
marinePBDB, for Trilobita

Time the record covers

At most 23 million years on record.

Every occurrence read is dated to somewhere between 410.62 Mya and 387.95 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Devonian — about 8 of 8 occurrencesDevonian411–410 Mya — about 0.0 occurrences410–410 Mya — about 0.0 occurrences410–409 Mya — about 0.0 occurrences409–408 Mya — about 0.0 occurrences408–407 Mya — about 0.0 occurrences407–406 Mya — about 0.0 occurrences406–406 Mya — about 0.0 occurrences406–405 Mya — about 0.0 occurrences405–404 Mya — about 0.0 occurrences404–403 Mya — about 0.0 occurrences403–402 Mya — about 0.0 occurrences402–402 Mya — about 0.0 occurrences402–401 Mya — about 0.0 occurrences401–400 Mya — about 0.0 occurrences400–399 Mya — about 0.2 occurrences399–398 Mya — about 0.7 occurrences398–398 Mya — about 0.7 occurrences398–397 Mya — about 0.7 occurrences397–396 Mya — about 0.7 occurrences396–395 Mya — about 0.7 occurrences395–395 Mya — about 0.7 occurrences395–394 Mya — about 0.7 occurrences394–393 Mya — about 0.5 occurrences393–392 Mya — about 0.3 occurrences392–391 Mya — about 0.3 occurrences391–391 Mya — about 0.3 occurrences391–390 Mya — about 0.3 occurrences390–389 Mya — about 0.3 occurrences389–388 Mya — about 0.3 occurrences388–387 Mya — about 0.1 occurrences411.1 Mya387.4 Mya

8 occurrences of Hollardops on record, most of them in the Devonian. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.

When

8 occurrences

These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.

Found in

4 formations

Timrhanrhart — 29.71°N, 6.70°WTimrhanrhart — 29.75°N, 6.71°WChefar el Ahmar — 29.56°N, 2.15°WEl Otfal — 30.97°N, 5.03°WAmerboh — 31.37°N, 4.05°W

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The named rock units Hollardops has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Hollardops and its relatives

Devonian

Where Hollardops and its relatives were recorded in the Devonian.

Found in the same rock

44 taxa

The Paleobiology Database records 6 sites for Hollardops, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.

This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.

Entered from

4 references

Each of the 8 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content2

Picture of Hollardops

Credit
Daderot
Licence
CC0
Commercial use
the licence allows it

3D model

Source
Sketchfab
Licence
CC Attribution
Commercial use
cannot be read from the licence given — check the record

Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.

The description on this site

Licence
CC BY-SA 4.0

This is what the site found, which is not the same as what exists.

Keep going

What may have been alongside itAcastidae through timeFormations of the DevonianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Morzadec 1997