# Talk:Horseshoe crab

I've recenly become aware that there's significant debate about where horseshoe crabs fit in chelicerates. All analyses show them as more derived than Sea Spiders, but multiple phylogenies (especially recent ones) have recovered this group as arachnids. RenaMoonn (talk) 20:09, 28 October 2024 (UTC)

@RenaMoonn I was in the neighborhood and saw this went up for review, so I took a look. I am not conducting this GA review but I do have notes since I am worried this article might not be ready. Morphological stasis, Evidence from genomic sequencing, one sentence in Growth and development, and Sexual size dimorphism sections are all missing citations. The lead and images are not compliant with MOS (MOS:SANDWICH and the lead is both too brief and formatted strangely). In general, this article relies heavily on one sentence paragraphs. The two morphological overview images are redundant. Please keep in mind that for any article (but especially for GA), all information needs to be cited by WP:Reliable, WP:Secondary sources.
This isn't meant to scare you away. Pursuing GA status for a vital article right out of the gate is ambitious and I applaud it (I honestly wish we had more people working on vital articles). Since you are a newer user, I highly recommend reaching out to the Peer review program to help give you some pointers. Likewise, working with the Wikipedia:Good article mentorship to review GAs will also give you a better view of what criteria/mistakes to look for in your own work. 🏵️Etrius ( Us) 15:36, 18 August 2024 (UTC)

Definitely gonna fix the four sub-categories you mentioned. Those were not my work, and due to them adding ~10,000 bytes of data, I assumed their citations would be satisfactory. Pissed that they couldn't be bothered to cite their sources.
Also noticed how the lead is cut off by the taxabox on mobile devices and am trying to fix this.
Still I have some questions. Mainly, I wanna understand your critique of the lead/synopsis. I'm confused why you think its formatting appears strange and am wondering about its ideal length. I'm also curious about what citations you think aren't reliable so i can correct them RenaMoonn (talk) 19:18, 18 August 2024 (UTC)
@RenaMoonn, I don't have any immediate concerns about sourcing reliability, save for me going in and reviewing source by source. I am just making a general comment, I haven't done any in-depth review. Per MOS:Lead, there is not expressed lead size but for a vital article of 80k bytes, I'd expect more than the current format of 2 line paragraphs. The lead is a summary, and thus, the longer the article the longer the lead (generally speaking). E.g. Spotted lanternfly is a GA I wrote a few years back that is a comparable length, the lead is 3 brief, but healthily sized paragraphs.
Honestly, condensing into 3 hearty paragraphs aught to be enough. I'm not expecting a dissertation. You have plenty of information on description, medical use, and behavior to fill this out. Plus, repeated, small sentences in the lead is just aesthetically unpleasing to look at. The body of the article doesn't suffer from nearly as bad of an issue as the lead. I am bringing this to your attention because the lead formatting, combined with the lack of citations would more often than not get quick-failed, and trust me, I know how much that feeling sucks when the article gets failed. 🏵️Etrius ( Us) 20:14, 18 August 2024 (UTC)
Welp, thanks for the suggestions. I formatted the lead following based off your article and the Isopoda page (a featured article) and also gave a lot of content citations. The only thing i might wanna do is expand the Diet subsection (it's a little lacking). I can't get too specific because the four species almost certainly eat different things (the Asian species are known to cohabitate), but i can at least do better than the two sentences i was left with. RenaMoonn (talk) 18:07, 22 August 2024 (UTC)

This review is transcluded from Talk:Horseshoe crab/GA1. The edit link for this section can be used to add comments to the review.
Nominator: RenaMoonn (talk · contribs) 18:08, 16 August 2024 (UTC)
Reviewer: Mgp28 (talk · contribs) 17:43, 22 August 2024 (UTC)

Hello, I am going to review this article against the good article criteria. This is my first review so if I seem to go off the path, please let me know. Mgp28 (talk) 17:43, 22 August 2024 (UTC)
GA review – see WP:WIAGA for criteria
Hello, I haven't yet finished the review. In particular, I plan to follow up on more of the references so my comments might change but I'm starting to share some thoughts below. I hope they are helpful. Please let me know if they're not. Mgp28 (talk) 07:59, 23 August 2024 (UTC)

Don't worry, your comments are definitely helpful. This is my first good article nomination so I'm in a similar position to you.
Also, am I allowed to change the article to accommodate your recommendations? RenaMoonn (talk) 17:42, 23 August 2024 (UTC)
Yes, from other reviews I've looked at I think that's common. Do you want to let me know when you've made changes and I'll go through the article again? Mgp28 (talk) 17:49, 23 August 2024 (UTC)
I will add further comments below. I will let you know when I have finished adding comments. Mgp28 (talk) 11:36, 23 August 2024 (UTC)


### well written?
#### The prose is clear and concise, and the spelling and grammar are correct
The sentence This contrasts with the lifestyle of extinct members, as some transitioned to living in freshwater could be clearer, perhaps with something like "Some extinct species of horseshoe crab lived in fresh water". Also mention the living species that lives in brackish water.
Instead of extends all back to the Ordovician, I would suggest "The earliest xiphosuran fossils date back 445 million years to the Ordovician". Then the next sentence, "Modern horseshoe crabs first appear in the fossil record approximately..."
The comment about 88 lineages -- is this 88 species?
Instead of the link to Incertae sedis, which will not be familiar to many readers, the uncertainty about genera should be explained in plain English.
Need more clarity about when breeding season is. Where is it year round? Is it only at full moon everywhere?
For reproduction, is it saying they only breed in the sand or mud in which they themselves hatched? I think this could be clearer.
Don't need "1,000,000" in brackets after "1 million"
Being arthropods... could be, "In common with all arthropods..."
In Sexual size dimorphism, I would describe the difference in size before explaining it. In this section I am left wondering how big is the difference, and don't find out until behavior and life history. I also think parts don't make sense. Point number 1 says that they have similar-size preferences in choosing a mate, but point 5 says there is no evidence of assortative mating. How can both be true?
I understand that these are different hypotheses but I still think it's confusing for readers of this article. Point 1 seems to rely on a fact that there is assortative mating and point 5 seems to rely there being no assortative mating. If these statements are part of the hypothesis then I think it needs to be rephrased. I'll take another look at the source article, although I will admit I didn't find that the easiest to follow when I skimmed through it rather rapidly.
Repetition of genome and redundancy of size in The genomes of C. rotundicauda and T. tridentatus have an unusually large genome size -- either the genomes are unusually large, or the species have unusually large genomes.
I went ahead and made an edit here to clarify the text
Following Femke's helpful comments, I have gone back through and reconsidered how things could be improved for a lay reader. I suggest,
When it says they are "benthic" animals, can we briefly describe what this means?
Could we replace extant with "living", or "still living", or add a parenthetical definition on its first use?
Could sexual size dimorphism be described as "size difference between the sexes"? 
extirpated -> "locally extinct"?


#### It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation
##### Lead sections
There are several points I would suggest adding to the lead:
An idea about how long ago they evolved in their current form, to help explain the "living fossil" statement
A bit more about their habitats, such as the ones that live in brackish water, and something about where they breed
The mention of bait, eating and harvesting blood doesn't seem to match with the article's main text. It starts occasionally used as fishing bait, whereas in the main text it sounds like measures are urgently needed because they are hunted so much. I would start with the main threat -- presumably the medical industry -- then the lesser threats can come after.
A mention of conservation efforts.


##### Layout
There is information about conservation in multiple sections, some of which repeats itself. Then it seems there is less about it in the actual Conservation status section. I suggest collating it all in one place.


##### Words to watch
"Nonetheless" feels like we are headed toward original research. I think the first paragraph of phylogeny could be rephrased -- I will try to come up with something clearer.
The source does not describe they immune system as "incredibly efficient". "Highly efficient" would match the source.
The word enigmatic is used in both of the sources for that sentence, but I still find it odd. Does the word have a technical meaning in this context?
Can we explain its meaning of difficult to place phylogenetically for the lay reader?
Thank you


##### Writing about fiction
Not applicable


##### Embedded lists
I think the section Evidence from genomic sequencing would be better as text.


### verifiable with no original research, as shown by a source spot-check?
#### It contains a list of all references (sources of information), presented in accordance with the layout style guideline
Several references appear repeatedly in the list, so I found I kept re-opening the same source. Some of these are for different pages. I would recommend combining all the repeated references and suggest using the {{rp}} template for different page numbers.
Thank you for sorting this


#### Reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose)
For this section I will use the numbering of the references as they are at present.
Reference 4 doesn't seem to use the phrase "living fossils" 
Reference 21 mentions morphological stability but I don't think it supports either the statement few, if any, mutations that would result in more beneficial alleles or This causes horseshoe crabs to have comparatively high rates of gene regulation, something that likely contributes to their morphological status.
A moratorium was restricted to male crabs in Delaware doesn't seem to be supported by the following reference
Thank you for the reference. I have also rephrased the sentence slightly.


### It contains no original research
I do worry that some parts are straying into original research, especially regarding genetics. Are there reviews or recent book chapters that summarize this information?


### It contains no copyright violations nor plagiarism
Looks good.


### Is it broad in its coverage?
#### It addresses the main aspects of the topic
Is horseshoe crab blood used in laboratories globally? Feels US focussed.


#### It stays focused on the topic without going into unnecessary detail (see summary style)
Possibly too much detail about licensing of Limulus clotting factor C, but no urgent need to change that


### Is it neutral?
#### It represents viewpoints fairly and without editorial bias, giving due weight to each
Yes.


### Is it stable?
#### It does not change significantly from day to day because of an ongoing edit war or content dispute
A lot of recent edits but mostly from the proposer. No edit wars.


### Is it illustrated, if possible, by images?
#### Images are tagged with their copyright status, and valid non-free use rationales are provided for non-free content
All look good


#### Images are relevant to the topic, and have suitable captions
The image showing the difference between male and female horseshoe crabs needs to describe which is the male and which is the female in the caption. 
Mgp28 (talk) 17:40, 23 August 2024 (UTC)


### Discussion
Mgp28 requested an experienced eye to give feedback on the review. In general, the review of a high quality :). You are right that reviews include a period of improvements by the nominators in response to comments. This should typically take around 7 days, but can sometimes take longer if necessary. A couple of things I would do differently:

When you spot check references, it's good practice to say how many references you've checked. If you check 3 sources, and all three have errors, there may be a systemic problem with the article and it may need to be failed. If you check 30 sources and 3 have errors, that can be fixed during the review.
The original research concerns refer to the instances of failed verification you found, right? If not, can you expand on it?
I would be stricter on making the article accessible to a wider public. For instance, "establish processes for evaluating alternative pyrogenicity tests and report back [to the Senate] on steps taken to increase their use" is overly technical, and it's unclear how it connects with the previous sentences. Ideally, quotes are used sparingly, mostly for creative outburst, not things that are easily paraphrased.
Usually reviews will contain slightly more prose suggestions for an article this size.
Overall, well done :). Let me know if either of you have any specific questions. —Femke 🐦 (talk) 19:31, 23 August 2024 (UTC)

Thank you for these really helpful comments. I'll go back through my review later and make some additional comments. I think I had more concerns about the phylogeny and evolution section, but will re-review and add more detail above. Mgp28 (talk) 08:10, 24 August 2024 (UTC)
Most of the pointers you gave earlier have been fixed, I just saved the worst part (the phylogeny and evolution section) for last
Here’s a Google doc with my changes (green), things I didn’t want to change (orange), things I haven’t changed (black), and commentary
https://docs.google.com/document/d/1QHjgqsouc83czRSr_ZIZ-sPIh-tSR74R9SzvNBZo6wo/edit RenaMoonn (talk) 15:01, 24 August 2024 (UTC)
Totally agree with making the article more accessible. You should’ve seen what I was working with in the original Evolution section. It was FAR worse than it is now. If you wanna see what it looked like, go back to before I started making edits. RenaMoonn (talk) 15:04, 24 August 2024 (UTC)
I feel it's looking a lot better now, thank you. I've struck out the comments that have been addressed and have added some additions above. I've tried not to add too much – some technical words are inevitable and where they are hyperlinks I'm hoping that readers can follow those for further clarity – but I think there are some technical terms that will need to be explained.
Regarding my comment on original research, I think it mostly was in terms of the problems I had already mentioned regarding sources. My broader concern is that it is all based on primary sources. I think the article accurately reflects what those sources say, but if possible I would prefer to have secondary sources that synthesize this material. As a reader, I feel I am implicitly synthesizing it myself to conclude they are not arachnids, but it would be nice if a review or book explained why the analysis that said they are arachnids was incorrect. Mgp28 (talk) 10:37, 25 August 2024 (UTC)
At least from my experience in paleontology research, phylogenies typically aren't synthesized in that way. People will add new taxa to a phylogeny (like the second study did) but there aren't really outside reviews explaining why the new phylogeny is better.
Also the reason why the arachnid-placement phylogeny is wrong is WAY too niche and jargony for this article. Makes me ashamed too as i want to do paleogenomics stuff later in life, but i haven't been trained on how to understand the specifics.
Anyways, I think i got all the article stuff i wanted to change fixed (mainly problems with the lead and phylogeny and evolution section) so you can do the final review now! RenaMoonn (talk) 02:38, 26 August 2024 (UTC)
Hi RenaMoonn, Thank you for this. It's a shame that some material had to be removed, but better to be shorter than inaccurate. I'll try to get the final review done tomorrow. Mgp28 (talk) 18:26, 28 August 2024 (UTC)
I've made a few edits to the article. I hope that's OK. The instructions said to be bold if the article was nearly there. I've struck out almost all of my comments above as they have been addressed. I think the article has improved a lot over the past week, and I hope you do too.
I realised I never answered Femke's comment about how many sources I had checked up on. I'm afraid I don't know exactly. The first time I went through the article there were duplicate references and I got myself into a bit of a muddle as I had the same sources opening in multiple tabs, but judging by how many of the hyperlinks have changed colour, it looks like I have visited at least 21 sources. I believe this article now meets the criteria and I am going to mark it as a good article! Mgp28 (talk) 16:41, 29 August 2024 (UTC)
PS I had made comments about the use of horseshoe-crab blood in the US vs globally, but looking back I don't think that is actually an accurate criticism. The bit about regulation of the alternative to the blood is perhaps a little US-centric, but it's discussed in terms of conservation of the animals that are harvested in the US, so I am also striking that. Mgp28 (talk) 17:05, 29 August 2024 (UTC)


### Discussion
I have enjoyed this process. The comments that I made on my initial reviews (listed above) were addressed and I believe the article meets the good article criteria. I have added the GA header to the talk page, and I have listed the article at Wikipedia:Good articles § Arthropods. Congratulations on the good article!
If anyone has any feedback about the review, please let me know. Mgp28 (talk) 17:05, 29 August 2024 (UTC)

Horseshoe Crab and to the Carnivorous Dinosaurs a Eustreptospondylus 49.49.88.189 (talk) 08:10, 20 January 2025 (UTC)

Huh? RenaMoonn (talk) 11:05, 9 February 2025 (UTC)

Who changed the origin from lower Ordovician to lower Triassic? There is a lot of Paleozoic Horseshoe crab material! 109.38.151.154 (talk) 08:48, 31 May 2025 (UTC)

That would be me, the editor who improved this article to GA status. This article is about Limulidae rather than Xiphosura as a whole, so mentioning they originated in the lower Triassic makes more sense.
I’m more comfortable calling Limulidae “horseshoe crabs” than Xiphosura as a whole, as Xiphosurans adopted a wide range of morphologies that weren’t all horseshoe shaped (ex: Austrolimulus, which looks like a pickaxe) RenaMoonn (talk) 23:17, 5 June 2025 (UTC)
That’s just an opinion as many papers call other xiphosurans horseshoe crabs like https://pmc.ncbi.nlm.nih.gov/articles/PMC12173487/ Houcaris  20:11, 1 October 2025 (UTC)